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BEGIN:VEVENT
SUMMARY:Ergün Yalçın (Bilkent University)
DTSTART:20201009T100000Z
DTEND:20201009T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/1
DESCRIPTION:Title: The Dade Group of a Finite Group and Dimension Functions<
/a>\nby Ergün Yalçın (Bilkent University) as part of Yeditepe Mathemati
cs Seminars\n\n\nAbstract\nLet $G$ be a finite group and $k$ an algebraica
lly closed field of characteristic\n$p > 0$. We define the notion of a Dad
e $kG$-module as a generalization of endopermutation modules for $p$-group
s. We show that under a suitable equivalence relation\, the set of equival
ence classes of Dade $kG$-modules forms a group under tensor product\, and
the group obtained this way is isomorphic to the Dade group $D(G)$ define
d by Lassueur $[2]$.\n\nWe also consider the subgroup $D^\\Omega (G)$ of
$D(G)$ generated by relative syzygies\n$\\Omega X$\, where $X$ is a finite
$G$-set. Let $C(G\; p)$ denote the group of superclass\nfunctions defined
on the p-subgroups of G. There are natural generators $\\omega_X$\nof $C(
G\; p)$. We prove that there is a well-defined group homomorphism $\\psi_G
:\nC(G\; p) \\to D^\\Omega (G)$ that sends $\\omega_X$ to $ \\Omega_X$.\
n\nThe main theorem is the verification that the subgroup of $C(G\; p)$ co
nsisting\nof the dimension functions of $k$-orientable real representation
s of $G$ lies in the\nkernel of $\\psi_G$. In the proof we consider Moore
$G$-spaces which are the equivariant\nversions of spaces which have nonzer
o reduced homology in only one dimension.\n\nThis talk is about a theorem
in modular representation theory whose proof is\ntopological using equivar
iant homotopy theory and homological algebra over\norbit category. I will
give all necessary definitions to make it possible to follow\nthe talk and
provide examples to motivate the theorems.\n\nThis is a joint work with M
atthew Gelvin $[1]$.\n\n$\\mathbf{References}$\n\n$[1]$ M. Gelvin and E. Y
alçın\, Dade Groups for Finite Groups and Dimension Functions\, preprint
\, 2020 (arXiv:2007.05322v2).\n\n$[2]$ C. Lassueur\, The Dade group of a f
inite group\, J. Pure Appl. Algebra\, 217 (2013)\,\n97-113.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aslı Güçlükan İlhan (Dokuz Eylül University)
DTSTART:20201016T100000Z
DTEND:20201016T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/2
DESCRIPTION:Title: $\\omega$-Weighted Digraphs and Local Complementations\nby Aslı Güçlükan İlhan (Dokuz Eylül University) as part of Yedite
pe Mathematics Seminars\n\n\nAbstract\nIn this talk\, we introduce $\\omeg
a$-weighted digraphs for a given dimension function $\\omega$. We generali
ze the notion of a local complementation to $\\omega$-weighted digraphs. T
hen we establish a bijection between isomorphism classes of $\\omega$-weig
hted digraphs up to local complementations and the isomorphism classes of
weakly $\\mathbb{Z}_2^n$-equivariant small covers over a product of simpli
ces.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kazım İlhan İkeda (Boğaziçi University)
DTSTART:20201030T100000Z
DTEND:20201030T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/3
DESCRIPTION:Title: On the Langlands reciprocity and functoriality principles
\nby Kazım İlhan İkeda (Boğaziçi University) as part of Yeditepe
Mathematics Seminars\n\nAbstract: TBA\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atabey Kaygun (İstanbul Technical University)
DTSTART:20201106T140000Z
DTEND:20201106T150000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/4
DESCRIPTION:Title: Generalized Weyl Algebras\, Birational Equivalences and G
elfand Kirillov Conjecture\nby Atabey Kaygun (İstanbul Technical Univ
ersity) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nRank $1$ g
eneralized Weyl algebras (GWAs) form an interesting class of algebras that
include (quantum) enveloping algebra of $sl(2)$ and some interesting quan
tum groups of rank $1$ and $2$. In this talk I will define GWAs and then e
xplain how these examples fit into the framework of GWAs. Birational equiv
alence\, on the other hand\, is a tool (commutative) algebraic geometers u
se quite extensively. Interestingly\, GWAs are birationally equivalent to
a smash product with a torus of rank $1$. Time permitting\, I will talk ab
out how all of these relate to Gelfand-Kirillov conjecture.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Özgün Ünlü (Bilkent University)
DTSTART:20210108T100000Z
DTEND:20210108T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/5
DESCRIPTION:Title: Free Group Actions on Products of Two Equidimensional Sph
eres\nby Özgün Ünlü (Bilkent University) as part of Yeditepe Mathe
matics Seminars\n\n\nAbstract\nWe will first review some known restriction
s on finite groups\nthat can act freely on products of two equidimensional
spheres. Then we\nwill discuss some constructions of free actions of fin
ite p-groups on\nproducts of two equidimensional spheres. Finally\, we wil
l discuss some\nopen problems about free p-group actions on two equidimens
ional spheres.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Turgut Önder (Middle East Techinal University)
DTSTART:20201204T140000Z
DTEND:20201204T150000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/6
DESCRIPTION:Title: Existence of Almost Complex Foliations on Spheres\nby
Turgut Önder (Middle East Techinal University) as part of Yeditepe Mathe
matics Seminars\n\n\nAbstract\nIntuitively\, a foliation on a manifold cor
responds to a partition of the manifold into connected\, immersed submanif
olds of the same dimension\, called leaves which form locally layers of a
Euclidean space. An almost complex foliation is a foliation whose tangent
bundle admits a complex structure. The existence problem of foliations on
closed manifolds is reduced to the existence problem of plane fields in 19
70’s by W. Thurston which can be attacked by algebraic topological metho
ds. However\, not much has been written about the existence problem of alm
ost complex foliations. On spheres\, İ. Dibağ’s results provide concre
te necessary conditions in terms of the dimension of the sphere and the di
mension of the foliation. In this talk\, after reviewing some basic notion
s about the foliations\, we will present some results in the other directi
on\, i.e. about the sufficient conditions for the existence of almost comp
lex foliations on spheres.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Özgür Kişisel (Middle East Techinal University)
DTSTART:20201211T140000Z
DTEND:20201211T150000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/7
DESCRIPTION:Title: On complex 4-nets\nby Özgür Kişisel (Middle East T
echinal University) as part of Yeditepe Mathematics Seminars\n\n\nAbstract
\nNets are certain special line arrangements in the plane and they occur i
n various contexts related to algebraic geometry\, such as resonance varie
ties\, homology of Milnor fibers and fundamental groups of curve complemen
ts. We will investigate nets in the complex projective plane $\\mathbb{CP}
^2$. Let $m\\geq 3$ and $d\\geq 2$ be integers. An $(m\,d)$-net is a penci
l of degree $d$ algebraic curves in $\\mathbb{CP}^2$ with a base locus of
exactly $d^2$ points\, which degenerates into a union of $d$ lines $m$ tim
es. It was conjectured that the only $4$-net is a $(4\,3)$-net called the
Hessian arrangement. I will outline our proof together with A. Bassa of th
is conjecture.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fatih Erman (İzmir İnstitute of Technology)
DTSTART:20201218T100000Z
DTEND:20201218T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/8
DESCRIPTION:Title: On the Existence of a Self-Adjoint Hamiltonian for a Sing
ular Interaction on Manifolds\nby Fatih Erman (İzmir İnstitute of Te
chnology) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nAccordin
g to the postulates of Quantum Mechanics\, the dynamics of quantum systems
are generated by a self-adjoint operator\, namely Hamiltonian operator as
sociated with the energy of the system. Dirac delta potentials are known a
s one class of singular interactions\, which have many applications in var
ious areas of physics. There are different mathematically rigorous approac
hes for the description of such systems by some self-adjoint Hamiltonian o
perator in $L^2(\\mathbb{R}^n)$. In this talk\, I would like to introduce
the subject in a rather elementary way and briefly discuss such interactio
ns in one dimension heuristically and from the Von Neumann's self-adjoint
extension point of view. Then\, I shall extend the same model onto the two
and three dimensional Cartan-Hadamard manifolds with Ricci curvature boun
ded below by describing the system in terms of "limit" of resolvent of the
regularized version of the initial singular Hamiltonian. This will be acc
omplished by the heat kernel defined on manifolds and its Li-Yau type of e
stimates.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Noyan Er (Dokuz Eylül University)
DTSTART:20201225T100000Z
DTEND:20201225T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/9
DESCRIPTION:Title: Pure Things\nby Noyan Er (Dokuz Eylül University) as
part of Yeditepe Mathematics Seminars\n\n\nAbstract\nThis will be a down-
to-earth that talk aims to spark interest\, especially among young researc
hers\, in a notion at the crossroads of several fields of algebra\, includ
ing representation theory of algebras\, abelian group theory and ring theo
ry\, namely purity. However\, whatever the path it may have followed histo
rically\, we will derive our motivation from a subject accessible to prett
y much every one with a basic understanding of linear algebra: systems of
linear equations.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Serdar Ay (Bilkent University)
DTSTART:20200508T100000Z
DTEND:20200508T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/12
DESCRIPTION:Title: Dilations of positive semidefinite kernels valued in ope
rators of barrelled VH-spaces\nby Serdar Ay (Bilkent University) as pa
rt of Yeditepe Mathematics Seminars\n\n\nAbstract\nA VH-space (Vector Hilb
ert Space in the sense of Loynes) is a complex complete locally convex spa
ce with a topologically ordered $*$-space valued inner product. Examples o
f VH-spaces include the chain of locally Hilbert $C^*$-modules\, Hilbert $
C^*$-modules and Hilbert Spaces.\n \nIn this talk\, after a brief discuss
ion of VH-Spaces with examples and basic properties\, we state a general d
ilation theorem for positive semidefinite kernels valued in adjointable op
erators on a barrelled VH-space. We prove that\, under barrelledness assum
ption\, a necessary and sufficient condition for the existence of a natura
l VH-space dilation\, or equivalently\, a reproducing kernel VH-space repr
esentation of the kernel\, is satisfied automatically.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mehmet Akif Erdal (Yeditepe University)
DTSTART:20200306T100000Z
DTEND:20200306T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/13
DESCRIPTION:Title: Brown Fibration Categories and Enrichments in Monoidal M
odel Categories\nby Mehmet Akif Erdal (Yeditepe University) as part of
Yeditepe Mathematics Seminars\n\n\nAbstract\nIn this talk we will discuss
Browns categories of fibrant objects that are induced by enrichments over
symmetric monoidal model categories. We will also show that various categ
ories of operator algebras\, and their equivariant versions\, are examples
of categories of fibrant objects induced by enrichments. By using this\,
we recover known results that equivariant $KK$ and $E$-theories are triang
ulated.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tuna Bayraktar (Yeditepe University)
DTSTART:20200417T100000Z
DTEND:20200417T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/14
DESCRIPTION:Title: Minimal surfaces and smooth autonomous dynamical systems
in 2D\nby Tuna Bayraktar (Yeditepe University) as part of Yeditepe Ma
thematics Seminars\n\n\nAbstract\nIn this talk\, an autonomous dynamical
system on a two-dimensional manifold $M$ will be identified with an exteri
or differential system $\\left(\\Sigma\,\\mathcal{I}\\right)$\, where $\\S
igma$ is a three-dimensional Riemannian manifold in $\\mathbb{R}\\times TM
\\simeq J^1(\\mathbb{R}\,M)$ and $\\mathcal{I}$ is the Pfaffian system gen
erated by the contact forms on $\\Sigma$. We will show that it is possible
to construct a minimal but not necessarily totally geodesic surface in $\
\Sigma$ characterized by the corresponding dynamical system. As a particul
ar case\, a nontrivial minimal surface in the Heisenberg group will be dis
cussed.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Degtyarev (Bilkent University)
DTSTART:20210507T100000Z
DTEND:20210507T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/16
DESCRIPTION:Title: Counting lines\, curves\, planes… in algebraic varieti
es\nby Alexander Degtyarev (Bilkent University) as part of Yeditepe Ma
thematics Seminars\n\n\nAbstract\nI will start from several classical but
very simple\, almost high school level\, examples of algebraic varieties c
ontaining many lines\, planes\, etc. These varieties are very special\, as
a typical one from the same family would have no lines at all. This bring
s up a natural problem of finding the *maximal* possible number of lines\,
planes\, etc. that can be contained in a member of a fixed family (say\,
hypersurfaces of a given dimension and degree). In general\, this problem
is wide open\, but I will describe an approach that lets one attack it for
a wide variety of seemingly unrelated families. Finally\, if time permits
\, I will cite a few recent results.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Selçuk Demir (Dokuz Eylül University)
DTSTART:20210521T130000Z
DTEND:20210521T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/17
DESCRIPTION:Title: On Some Entropy Inequalities\nby Selçuk Demir (Doku
z Eylül University) as part of Yeditepe Mathematics Seminars\n\n\nAbstrac
t\nI plan to give a survey of an approach of Besenyei and Petz to some ent
ropy inequalities related to the so-called strong subadditivity. I will di
scuss a related conjecture and give a\nreport on its current status. Most
of the talk will be an introduction to this area for mathematicians and wi
ll hopefully be accessible to graduate students of mathematics.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Semra Pamuk (Middle East Technical University)
DTSTART:20210312T130000Z
DTEND:20210312T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/18
DESCRIPTION:Title: Rank conditions for finite group actions on $4$-manifold
s\nby Semra Pamuk (Middle East Technical University) as part of Yedite
pe Mathematics Seminars\n\n\nAbstract\nIn this talk\, I will give some old
and new information about the existence of finite group actions on closed
\, connected\, orientable $4$-manifolds. In this dimension\, the compariso
n between smooth and topological group actions are interesting but our foc
us will be on locally linear topological actions. In particular\, we will
talk about the following question: Given a closed orientable $4$-manifold
$M$\, what is the maximum value of $\\mathrm{rk}(G)$ over all the finite g
roups $G$ which act effectively\, locally linearly\, and homologically tri
vially on $M$? This is a joint work with Ian Hambleton.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fatma Altunbulak Aksu (Mimar Sinan Fine Arts University)
DTSTART:20210604T130000Z
DTEND:20210604T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/19
DESCRIPTION:Title: Group codes: an application of group algebras to coding
theory\nby Fatma Altunbulak Aksu (Mimar Sinan Fine Arts University) as
part of Yeditepe Mathematics Seminars\n\n\nAbstract\nBerman and MacWillia
ms independently define group codes as ideals in finite group algebras. Ma
ny linear codes can be viewed as group codes. For example\, cyclic codes c
an be considered as ideals in finite group algebras of cyclic groups and R
eed Muller codes over $\\mathbb{F}_p$ can be viewed as ideals in modular g
roup algebra of an elementary abelian $p$-group. Group codes have richer
algebraic structures than linear codes\, for that reason\, considering cod
es as group codes have many advantages. Algebraic tools in ring theory and
character theory can be used to understand codes via group codes. In this
talk I will give a gentle introduction for group codes and state some pr
oblems and results in the literature. If time permits\, I will state some
recent contributions which are joint work with İpek Tuvay.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Engin Büyükaşık (İzmir Institute of Technology)
DTSTART:20210528T130000Z
DTEND:20210528T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/20
DESCRIPTION:Title: Dual Baer Criterion and R-projectivity of injective modu
les\nby Engin Büyükaşık (İzmir Institute of Technology) as part o
f Yeditepe Mathematics Seminars\n\n\nAbstract\nLet $R$ be a ring with unit
y and Mod-$R$ be the category of right $R$-modules. The Baer's Criterion f
or injectivity states that a right module $M$ is injective iff it is $R$-i
njective\, that is for each right ideal $I$ of $R$\, any homomorphism fro
m $I$ into $M$ extends to $R$. Dually\, a right module $P$ is $R$-projecti
ve if for each right ideal $I$ of $R$ any homomorphism from $M$ into $R/I
$ lifts to $R$. Unlike the case for injectivity\, $R$-projective modules n
eed not be projective. That is\, the Dual Baer Criterion (DBC\, for short)
does not hold over every ring. The rings $R$ for which the DBC holds in
Mod-$R$ are called right testing. From [4]\, it is known that right perfec
t rings are right testing. In [3]\, Faith stated the characterization of
all right testing rings as an open problem. Recently in [6]\, Trlifaj pro
ved that the problem of characterizing right testing rings is undecidable
in ZFC.\n\nIn this talk\, after summarizing the aforementioned results\, I
will mention an extend of the notion of $R$-projectivity\, and discuss s
ome problems related to the rings whose injective right modules are $R$-pr
ojective which are partially solved in [1].\n\nReferences\n\n[1] Y. Alagö
z and E. Büyükaşık\, Max-projective modules\, J. Algebra Appl. 20 (202
1)\, no. 6. 2150095.\n\n[2] H. Alhilali\, Y. Ibrahim\, G. Puninski\, and M
. Yousif\, When R is a testing module for projectivity? J. Algebra 484 (20
17)\, 198-206.\n\n[3] C. Faith\, Algebra. II\, Springer-Verlag\, Berlin-Ne
w York\, 1976. Ring theory\, Grundlehren der Mathematischen Wissenschaften
\, No. 191.\n[4] F .L. Sandomierski\, Relative injectivity and projectivit
y\, 1964. Thesis (Ph.D.) The Pennsylvania\nState University.\n\n[5] J. Trl
ifaj\, Whitehead test modules\, Trans. Amer. Math. Soc. 348 (1996)\, no. 4
\, 1521-1554.\n\n[6] J. Trlifaj\, Faith’s problem on R-projectivity is u
ndecidable\, Proc. Amer. Math. Soc. 147 (2019)\,\nno. 2\, 497-504.\n\n[7]
J. Trlifaj\, The dual Baer Criterion for non-perfect rings\, Forum Math. 3
2 (2020)\, no. 3\, 663-672.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alp Bassa (Boğaziçi University)
DTSTART:20210409T130000Z
DTEND:20210409T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/21
DESCRIPTION:Title: Rational points on curves over finite fields and their a
symptotic\nby Alp Bassa (Boğaziçi University) as part of Yeditepe Ma
thematics Seminars\n\n\nAbstract\nCurves over finite fields with many rati
onal points have been of interest for both theoretical reasons and for app
lications. To obtain such curves with large genus various methods have bee
n employed in the past. One such method is by means of explicit recursive
equations and will be the emphasis of this talk. The recursive nature of t
hese towers makes them very special and in fact all good examples have bee
n shown to have a modular interpretation of some sort. In this talk I will
try to give an overview of the landscape of explicit recursive towers and
their modularity.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Müge Kanuni Er (Düzce University)
DTSTART:20210416T100000Z
DTEND:20210416T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/22
DESCRIPTION:Title: Socle of Incidence Rings\nby Müge Kanuni Er (Düzce
University) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nIn hi
s seminal paper of 1964\, "On the foundations of combinatorial theory I: T
heory of Möbius Functions" Gian-Carlo Rota defined an incidence ring as a
tool for solving combinatorial problems. Incidence ring is a specific rin
g of functions defined on the ordered pairs of a given partially ordered s
et to a given ring. Möbius function is an element of an incidence ring\,
besides with the appropriate choice of the partially ordered set\, Möbius
function of this incidence algebra coincides with the well-known Möbius
function of number theory. A product of copies of a ring and upper triangu
lar matrices are typical examples of incidence algebras. \n\nThe investiga
tion of a ring is usually enriched by understanding specialtypes of ideals
of it\, such as the Jacobson radical\, the prime radical\, the socle\,the
singular ideal\, the center\, etc. Although incidence rings have been an
object of study for a few decades\, there does not seem to be any results
in the literature on the socle of incidence rings.\n\nIn this talk\, we wi
ll be restricting the left socle of an incidence ring between two sets.Mor
e explicitly\, we compute the socle of an incidence ring I(X\,R) under so
me assumptions on the ring R and/or the partially ordered set X. \n\n(This
joint work with Özkay Özkan- https://doi.org/10.15672/hujms.684042 )\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Benjamin Matschke (Boston University)
DTSTART:20210319T150000Z
DTEND:20210319T160000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/23
DESCRIPTION:Title: Proofs by example\nby Benjamin Matschke (Boston Univ
ersity) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nWe study t
he proof method "proof by example" in which a general statement can be pro
ved by verifying it for a single example. This strategy can indeed work if
the statement in question is an algebraic identity and the example is "ge
neric". This talk addresses the problem of constructing a practical exampl
e\, which is sufficiently generic\, for which the statement can be verifie
d efficiently\, and which allows for a numerical margin of error.\n\nOur m
ethod is based on diophantine geometry\, in particular an arithmetic Bezou
t theorem\, an arithmetic Nullstellensatz\, and a new effective Liouville-
Lojasiewicz type inequality for algebraic varieties. As an application we
discuss theorems from plane geometry and how to\nprove them by example.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Oğuz Şavk (Boğaziçi University)
DTSTART:20210305T130000Z
DTEND:20210305T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/24
DESCRIPTION:Title: Classical and New Plumbings Bounding Contractible Manifo
lds and Homology Balls\nby Oğuz Şavk (Boğaziçi University) as part
of Yeditepe Mathematics Seminars\n\n\nAbstract\nA central problem in low-
dimensional topology asks which\nhomology 3-spheres bound contractible 4-m
anifolds and homology 4-balls.\nIn this talk\, we address this problem for
plumbed 3-manifolds and we\npresent the classical and new results togethe
r. Our approach is based on\nMazur’s famous argument which provides a un
ification of all results in a\nfairly simple way.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Berrin Şentürk (TED University)
DTSTART:20210430T130000Z
DTEND:20210430T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/25
DESCRIPTION:Title: Free Group Actions on Product of 3 Spheres\nby Berri
n Şentürk (TED University) as part of Yeditepe Mathematics Seminars\n\n\
nAbstract\nA long-standing Rank Conjecture states that if an elementary ab
elian $p$-group acts freely on a product of spheres\, then the rank of the
group is at most the number of spheres in the product. We will discuss th
e algebraic version of the Rank Conjecture given by Carlsson for a differe
ntial graded module $M$ over a polynomial ring. We will state a stronger c
onjecture concerning varieties of square-zero upper triangular matrices co
rresponding to the differentials of certain modules. By the work on free f
lags in $M$ introduced by Avramov\, Buchweitz\, and Iyengar\, we will obta
in some restriction on the rank of submodules of these matrices. By this a
rgument we will show that $(\\mathbb{Z}/2\\mathbb{Z})^4$ cannot act freely
on product of $3$ spheres of any dimensions.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Uğur Yiğit (İstanbul Medeniyet University)
DTSTART:20210402T130000Z
DTEND:20210402T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/26
DESCRIPTION:Title: $C_2$-Equivariant EHP Sequences\nby Uğur Yiğit (İ
stanbul Medeniyet University) as part of Yeditepe Mathematics Seminars\n\n
\nAbstract\nTo determine the homotopy groups $\\pi_n(S^k)$ of spheres is a
central problem in homotopy\ntheory. One of the main tools for calculatio
ns in the classical unstable homotopy theory is\nthe EHP sequence. In this
talk\, we give the generalizations of the EHP sequence in the classical h
omotopy theory to the $C_2$-equivariant case.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ayhan Günaydin (Boğaziçi University)
DTSTART:20210611T130000Z
DTEND:20210611T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/27
DESCRIPTION:Title: Model Theory of Beatty Sequences\nby Ayhan Günaydin
(Boğaziçi University) as part of Yeditepe Mathematics Seminars\n\n\nAbs
tract\nThe Beatty Sequence generated by an irrational r>1 is ([nr] : n>0)\
, where [c] denotes the integer part of a real number c. A well-known prop
erty of this sequence is that "any pattern that appears once has to appear
infinitely many times\; moreover we may determine when a pattern appears
next time with a small error". After explaining what this means\, we will
present the proof of a strengthening of it. Our proof depends on the model
theoretic study of the sequence and all the necessary background will be
overviewed. (This is a joint work with Melissa Özsahakyan.)\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yusuf Ünlü (Yeditepe University)
DTSTART:20211001T130000Z
DTEND:20211001T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/28
DESCRIPTION:Title: The impossibility of the angle trisection by straightedg
e and compass revisited\nby Yusuf Ünlü (Yeditepe University) as part
of Yeditepe Mathematics Seminars\n\n\nAbstract\nIt is well known that the
angle trisection or doubling the cube is impossible by using only ruler a
nd compass. The usual algebraic proof uses the fact that if a real number
$\\xi$ is constructible using only ruler and compass then there is a tower
of fields\n$$\\mathbb Q= F_0 \\subset F_1 \\subset \\cdots \\subset F_
n$$\nsuch that if $n \\geq 1$\, then $F_i = F_{i-1}(u_i)$ where $u_i\\noti
n F_{i-1}$ but $u_i^2\\in F_{i-1}$ and $\\xi \\in F_n$. Hence $2^m = [F_n
: \\mathbb Q]$ for some $m \\in \\mathbb N$. This shows that $$2^m = [F_n
: \\mathbb Q]= [F_n : \\mathbb Q(\\xi)][\\mathbb Q(\\xi) : \\mathbb Q]$$
\nSo\, if the minimal polynomial of $\\xi$ in $\\mathbb Q(x)$ is of odd d
egree\, then $\\xi$ is\nnot constructible by only ruler and compass. Moreo
ver\, the minimal\npolynomial of $\\cos 20^\\circ$ has degree $3$. So it i
s impossible to trisect $60^\\circ$ by\nusing only ruler and compass.\n\nH
owever\, this proof requires the fundamentals of vector spaces. In this ta
lk\, we wíll tweak the last part of the proof to avoid vector spaces.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cihan Okay (Bilkent University)
DTSTART:20211105T130000Z
DTEND:20211105T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/29
DESCRIPTION:Title: Homotopy classification of operator solutions of linear
systems\nby Cihan Okay (Bilkent University) as part of Yeditepe Mathem
atics Seminars\n\n\nAbstract\nLinear systems of equations over a finite fi
eld play an important role in quantum information theory. Instead of looki
ng for solutions over the base field one can look for solutions (in a cert
ain sense) over the unitary group\, which are called operator solutions. T
he data of this system of equations can be expressed using a hypergraph an
d the operator solutions can be studied from a topological point of view b
y considering certain topological realizations of these hypergraphs. In th
is talk I will describe how homotopical methods provide a way to classify
operator solutions of linear systems. Our basic approach is to interpret o
perator solutions as maps from a topological realization of the hypergraph
to a certain classifying space first introduced by Adem-Cohen-Torres Gies
e.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Oktay Pashaev (İzmir Institute of Technology)
DTSTART:20211008T130000Z
DTEND:20211008T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/30
DESCRIPTION:Title: Quantum Calculus of Fibonacci Divisors applied to Classi
cal Method of Images and Quantum Computational States\nby Oktay Pasha
ev (İzmir Institute of Technology) as part of Yeditepe Mathematics Semina
rs\n\n\nAbstract\nStarting from divisibility problem for Fibonacci numbers
\, we introduce integer Fibonacci divisors\, conjugate to $F_k$\, related
hierarchy of Golden derivatives in powers of the Golden Ratio and develop
corresponding quantum calculus. By the set of translation operators\, we f
ind the hierarchy of Golden binomials and related Golden analytic function
s. In the limit $k \\to 0\,$ these functions reduce to classical holomorph
ic functions and quantum calculus of Fibonacci divisors to the usual one.
The hierarchy of Golden periodic functions appearing in this calculus\, we
relate with classical method of images in planar hydrodynamics (electrost
atics). Several applications of the calculus to quantum deformed algebras
and quantum computation and information theory are discussed. In particula
r\, we show that for repeated consecutive duplicated qubit states\, probab
ilities are determined by Fibonacci numbers. We generalize these results f
or direct product of multiple qubit states and arbitrary position of repea
ted states. The calculations are based on structure of Fibonacci trees in
space of qubit states\, growing in the left and in the right directions\,
number of branches and allowed paths on the trees.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sefa Feza Arslan (Mimar Sinan Fine Arts University)
DTSTART:20211210T130000Z
DTEND:20211210T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/32
DESCRIPTION:Title: Numerical Semigroups\, Apery table and Hilbert functions
\nby Sefa Feza Arslan (Mimar Sinan Fine Arts University) as part of Ye
ditepe Mathematics Seminars\n\n\nAbstract\nIn this talk\, I will first int
roduce the concept of Apery table of a numerical semigroup introduced by C
ortedellas and Zarzuela (Tangent cones of numerical semigroup rings. Conte
mp. Math. 502\, 45–58 (2009)). After presenting some open problems about
Hilbert functions of local rings\, I will give some partial results in th
e case of local rings associated to numerical semigroups.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gülin Ercan (Middle East Technical University)
DTSTART:20211217T130000Z
DTEND:20211217T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/34
DESCRIPTION:Title: Good Action\nby Gülin Ercan (Middle East Technical
University) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nLet $G
$ be a group acted on by a group $A$ by automorphisms. The nature of this\
naction is very restrictive and hence informative about the structure of $
G$. We have\nbeen carrying on research in this area\, especially on length
type problems\, in several\ncollaborated works over the years. The action
is said to be coprime if $G$ and $A$ have\ncoprime orders. The existence
of nice conditions which are valid in this case made\nit almost traditiona
l to assume that the action is coprime. After many attacks to a\nlongstand
ing noncoprime conjecture we have recently introduced the concept of a\ngo
od action of $A$ on $G$ in a joint work with Güloğlu and Jabara. We say
the action\nis “good” if $H = [H\, B]C_H(B)$ for every subgroup $B$ of
$A$ and for every $B$-invariant\nsubgroup $H$ of $G$. It can be regarded
as a generalization of the coprime action due\nto the fact that every copr
ime action is good and there are noncoprime actions\nwhich are good. It is
expected that this concept may help to understand the real\ndifficulties
in studying a noncoprime action. We have achieved extending several\ncopri
me results to good action case. With this talk I aim to present a review o
f\nour results and discuss the main difficulties that arise in the study o
f a noncoprime\ngood action.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sibel Şahin (Mimar Sinan Fine Arts University)
DTSTART:20211015T130000Z
DTEND:20211015T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/35
DESCRIPTION:Title: de Branges-Rovnyak spaces $H(b)$ from unit disc to unit
ball of $\\mathbb C^n$\nby Sibel Şahin (Mimar Sinan Fine Arts Univers
ity) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nIn this talk
we will consider a special subclass of the Hardy-Hilbert space $H^2$ namel
y de Branges-Rovnyak spaces $H(b)$\, first with an introduction of model s
paces in the unit disc and then in the setting of the unit ball of $\\math
bb C^n$. One of the main problems in the study of $H(b)$ functions is thei
r integral representation and in this talk we will see how we can represen
t these classes through the Clark measure on $S^n$ associated with $b$. In
the second part we will give a characterization of admissible boundary li
mits in relation with finite angular derivatives and we will see the inter
play between Clark measures and angular derivatives showing that Clark mea
sure associated with $b$ has an atom at a boundary point if and only if $b
$ has finite angular derivative at the same point. More detailed analysis
of the concepts mentioned in this talk can be found in the following stud
y.\n\n\n[1] Şahin\, S.\, Angular Derivatives and Boundary Values of $H(b)
$ Spaces of Unit Ball of $\\mathbb C^n$\, Complex Variables and Elliptic E
quations\, Volume 66\, Issue 2\, pp:226-237\, (2021).\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nadia Romero (Universidad de Guanajuato)
DTSTART:20211119T150000Z
DTEND:20211119T160000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/36
DESCRIPTION:Title: Operations on the Frobenius-Wielandt morphism\nby Na
dia Romero (Universidad de Guanajuato) as part of Yeditepe Mathematics Sem
inars\n\n\nAbstract\nIn 1992\, Dress\, Siebeneicher and Yoshida introduced
the Frobenius-Wielandt morphism (FW morphism)\, defined from the Burnside
ring of a cyclic group C to the Burnside ring of a finite group G of orde
r |C|. A remark in their article indicates that their intention was "to gi
ve a precise conceptual interpretation of the observation that many elemen
tary group-theoretic results can be derived from the fact that various inv
ariants of an arbitrary group are closely related to the same invariant ev
aluated for the cyclic group C". Among other properties\, they investigate
d the relation of the FW morphism with the operations of restriction\, ind
uction\, inflation and fixed points. In this talk we will see what can be
said about the relation of the FW morphism with other operations related t
o the Burnside ring\, especifically: tensor induction and deflation.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Orendain (Universidad Nacional Autónoma de México)
DTSTART:20220404T163000Z
DTEND:20220404T173000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/37
DESCRIPTION:Title: End-indexings and lifts to framed bicategories\nby J
uan Orendain (Universidad Nacional Autónoma de México) as part of Yedite
pe Mathematics Seminars\n\n\nAbstract\nFramed bicategories are double cate
gories satisfying cerain fibrancy conditions. Many structures naturally or
ganize into framed bicategories\, e.g. relations\, profunctors\, adjoints\
, open Petri nets\, polynomials functors\, polynomial comonoids\, structur
ed cospans\, etc. Symmetric monoidal structures on framed bicategories des
cend to symmetric monoidal structures on horizontal bicategories. The axio
ms defining symmetric monoidal double categories are considerably more tra
ctible than those defining symmetric monoidal bicategories. It is thus con
venient to study ways of lifting a given bicategory into a framed bicatego
ry along an appropriate category of vertical morphisms. Solutions to the p
roblem of lifting bicategories to double categories have classically being
useful in expressing Kelly and Street's mates correspondence and in provi
ng the 2-dimensional Seifert-van Kampen theorem of Brown et. al.\, amongst
many other applications. We consider lifting problems in their full gener
ality.\n\nGlobularly generated double categories are minimal solutions to
lifting problems of bicategories into double categories along given catego
ries of vertical arrows. Globularly generated double categories form a cor
eflective sub-2-category of general double categories. This\, together wit
h an analysis of the internal structure of globularly generated double cat
egories yields a numerical invariant on general double categories. We call
this invariant the length. The length of a double category $C$ measures t
he complexity of mixed compositions of globular and horizontal identity sq
uares of $C$ and thus provides a measure of complexity for lifting problem
s of bicategories into $C$. It has long being conjectured by the author th
at framed bicategories are of length 1.\n\nI will explain recent results o
n the theory of globularly generated double categories\, the length invari
ant\, and the theory of framed bicategories\, making use of certain types
of indexings and opindexings on decorated bicategories.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kağan Kurşungöz (Sabancı University)
DTSTART:20220307T113000Z
DTEND:20220307T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/41
DESCRIPTION:Title: Capparelli's Identities and the Kanade-Russell Conjectur
es\nby Kağan Kurşungöz (Sabancı University) as part of Yeditepe Ma
thematics Seminars\n\n\nAbstract\nWe will review the basics of integer par
titions\, then we will give a very rough\, somewhat subjective\, classific
ation of partition identities. We will impress on the impact of Capparell
i's identities on integer partition theory\, and talk about Kanade-Russell
conjectures as time allows.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sultan Eylem Toksoy (Hacettepe University)
DTSTART:20220328T113000Z
DTEND:20220328T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/42
DESCRIPTION:Title: On some generalizations from Module Categories to Grothe
ndieck Categories by using Purity\nby Sultan Eylem Toksoy (Hacettepe U
niversity) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nThe not
ion of pure subgroups were first investigated by Prufer in [9]. Purity has
utmost importance in abelian group theory because it makes possible to us
e the methods of relative homological algebra as there are enough pure-inj
ective and enough pure-projective groups. The purity concept was extended
to modules over arbitrary rings by Cohn [3]\, Bourbaki [1]\, Butler and Ho
rrocks [2] and Walker [11]. Stenström generalized the notion of purity to
an abelian category with a (projective) generator in [10]. The notions of
Rickart and dual Rickart were introduced and studied for modules by Lee\,
Rizvi and Roman [6\, 7\, 8]. Rickart and dual Rickart modules have been g
eneralized to abelian categories by Crivei\, Kör and Olteanu [4\, 5]. In
this work\, (dual) purely Rickart objects are introduced as generalization
s of (dual) Rickart objects in Gröthendieck categories. Examples showing
the relations between (dual) relative Rickart objects and (dual) relative
purely Rickart objects are given. It is shown that in a spectral category
(dual) relative purely Rickart objects coincide with (dual) relative Ricka
rt objects. (Co)products of (dual) relative purely Rickart objects are stu
died. Classes all of whose objects are (dual) relative purely Rickart are
identified. Applications to comodule categories are given.\n\nReferences\n
\n[1] N. Bourbaki\, Elements of Mathematics\, Commutative Algebra\, Addiso
n-Wesley Publishing Company\, Advanced Book Program\, Reading Massachusett
s\, 1972. Originally published as: Elements De Mathematique\, Algebre Comm
utative\, Hermann\, Paris\, 1969.\n\n[2] M. C. R. Butler and G. Horrocks\,
Classes of Extensions and Resolutions\, Phil. Trans. Royal Soc. of London
\, Series A 254 (1961)\, 155–222.\n\n[3] P. M. Cohn\, On the Free Produc
t of Associative Rings\, Mathematische Zeitschrift 71 (1959)\, 380–398.\
n\n[4] S. Crivei and A. Kör\, Rickart and Dual Rickart Objects in Abelian
Categories\, Appl Categor Struct 24 (2016)\, 797–824.\n\n[5] S. Crivei
and G. Olteanu\, Rickart and Dual Rickart Objects in Abelian Categories: T
ransfer via Functors\, Appl Categor Struct 26 (2018)\, 681–698.\n\n[6] G
. Lee\, S. T. Rizvi and C. S. Roman\, Rickart Modules\, Comm. Algebra 38 (
2010)\, 4005–4027.\n\n[7] G. Lee\, S. T. Rizvi and C. S. Roman\, Dual Ri
ckart Modules\, Comm. Algebra 39 (2011)\, 4036–4058. \n\n[8] G. Lee\, S.
T. Rizvi and C. S. Roman\, Direct Sums of Rickart Modules\, J. Algebra 35
3 (2012)\, 62–78.\n\n[9] H. Prüfer\, Untersuchungen über die Zerlegba
rkeit der abzaehlbaren prim aeren Abelschen Gruppen\, Mathematische Zeitsc
hrift 17 (1923)\, 35–61.\n\n\n[10] B. T. Stenström\, Pure submodules\,
Arkiv För Matematik 7 (10) (1966)\, 159–171.\n\n[11] C. L. Walker\, Rel
ative Homological Algebra and Abelian Groups\, Illinois J. Math. 10 (1966)
\, 186–209\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Haldun Özgür Bayındır (City\, University of London)
DTSTART:20220411T113000Z
DTEND:20220411T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/43
DESCRIPTION:Title: Adjoining roots to ring spectra and algebraic K-theory\nby Haldun Özgür Bayındır (City\, University of London) as part of
Yeditepe Mathematics Seminars\n\n\nAbstract\nThe category of spectra captu
res an important part of the complexity of topological spaces while provid
ing generalizations of many important notions in homological algebra. \n\n
In this work\, we develop a new method to adjoin roots to ring spectra and
show that this process results in interesting splittings in algebraic K-t
heory.\n\nIn the first part of my talk\, I will provide motivation for alg
ebraic K-theory and highly structured ring spectra. After this\, I will di
scuss trace methods\, a program that provides computational tools for alge
braic K-theory\, and introduce our results.\n\nThis is a joint work in pro
gress with Tasos Moulinos and Christian Ausoni.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Esma Dirican Erdal (Yeditepe University)
DTSTART:20220321T113000Z
DTEND:20220321T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/45
DESCRIPTION:Title: On Reidemeister Torsion of Closed Stably Parallelizable
Manifolds\nby Esma Dirican Erdal (Yeditepe University) as part of Yed
itepe Mathematics Seminars\n\n\nAbstract\nLet $M$ be a closed orientable $
(n-2)$-connected $2n$-dimensional stably parallelizable manifold. Such an
$M$ admits a connected sum decomposition into simpler submanifolds. In
this talk\, by using such decompositions\, we will give multiplicative gl
uing formulas that express the Reidemeister torsion of $M$ with untwisted
real coefficients in terms of Reidemeister torsions of its building blocks
. This is a joint work with Yaşar Sözen.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Valery Romanovski (University of Maribor)
DTSTART:20220518T113000Z
DTEND:20220518T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/46
DESCRIPTION:Title: Integrability and limit cycles in polynomial systems of
ODE's\nby Valery Romanovski (University of Maribor) as part of Yedit
epe Mathematics Seminars\n\n\nAbstract\nWe discuss two problems related to
the theory of polynomial plane differential systems\, that is\, systems
of the form \n \\begin{equation} \\label{1}\n \\frac{dx}{dt}=P_{n}(x\,y
)\, \\ \\ \\ \n \\frac{dy}{dt}=Q_{n}(x\,y)\,\n \\end{equation}
\nwhere $P_{n}(x\,y
)\, Q_{n}(x\,y)$ are polynomials of degree $n$\, $x$ and $y$ are real unkn
own functions.\n \nThe first one is the problem of local integrability\,
that is\, the problem of finding local analytic integrals in a neighborho
od of singular points of system (1). We present a computational approach
to find integrable systems within given parametric families of systems a
nd describe some mechanisms of integrability. \n \nThe second problem
is called the cyclicity problem\, or the local 16th Hilbert problem\, and
is related to the estimation of the number of limit cycles arising in sys
tem (1) after perturbations of integrable systems. The approach is algorit
hmic and is based on algorithms of computational commutative algebra relyi
ng on the Groebner bases theory.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:İpek Tuvay (Mimar Sinan Fine Arts University)
DTSTART:20220425T113000Z
DTEND:20220425T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/47
DESCRIPTION:Title: On minimal abelian group codes\nby İpek Tuvay (Mima
r Sinan Fine Arts University) as part of Yeditepe Mathematics Seminars\n\n
\nAbstract\nGroup codes are special types of linear codes that carry more
algebraic structure. They can be seen as ideals of group algebras and beca
use of this\, representation theoretic techniques help us to understand th
ese codes better. When the group algebra is semisimple\, any group code is
a direct sum of minimal ones. \n\nIn this talk\, first group codes will b
e introduced together with different types of examples. Then an equivalenc
e relation among the minimal codes will be introduced and open problems co
ncerning this notion will be stated. Afterwards\, recent contributions to
the solution of these open problems will be given. This is a joint work wi
th Fatma Altunbulak Aksu.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mehmet Akif Erdal (Yeditepe University)
DTSTART:20220523T113000Z
DTEND:20220523T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/49
DESCRIPTION:Title: Vector bundles that appear as normal bundles of manifold
s\nby Mehmet Akif Erdal (Yeditepe University) as part of Yeditepe Math
ematics Seminars\n\n\nAbstract\nGiven a Poincaré complex $X$\, a vector b
undle $\\xi$ over $X$ is said to be realized by the normal bundle of a man
ifold $M$\, if $\\xi$ is pulled back from the normal bundle of $M$ along a
homotopy equivalence $X\\rightarrow M$. The problem of determining such b
undles over an arbitrary Poincaré complex is a difficult problem and is r
elated to classical problems of surgery theory. In this talk\, we will dis
cuss some methods of approaching this problem and talk about solutions for
certain cases of $X$. In particular\, we will discuss conditions on bundl
es over $X$ that guarantee they are realized by normal bundles of manifold
s\, for $X$ belonging to a certain class of homology spheres.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nikolai Andreev (Steklov Mathematical Institute of RAS)
DTSTART:20220702T103000Z
DTEND:20220702T113000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/50
DESCRIPTION:Title: Mathematical Essence\nby Nikolai Andreev (Steklov Ma
thematical Institute of RAS) as part of Yeditepe Mathematics Seminars\n\nL
ecture held in Mathematics Department Seminar Room.\n\nAbstract\nOn the in
teractive lecture we will discuss the mathematical essence of the\ngreates
t achievements of civilization and the mathematical basis\nhabitual\, eve
ryday things and phenomena. We will use materials of the\nbook "Mathemati
cal essence" (http://book.etudes.ru/) authors of\nwhich are leading
mathematicians and films from the project "Mathematical\nEtudes" (ht
tp://www.etudes.ru/).\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kamuran Saygılı (İstanbul University)
DTSTART:20221014T113000Z
DTEND:20221014T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/51
DESCRIPTION:Title: A Course: Introduction to Mathematical Optics I\nby
Kamuran Saygılı (İstanbul University) as part of Yeditepe Mathematics S
eminars\n\n\nAbstract\nOutline of a course: Introduction to Mathematical O
ptics.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kamuran Saygılı (İstanbul University)
DTSTART:20221021T113000Z
DTEND:20221021T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/53
DESCRIPTION:Title: A Course: Introduction to Mathematical Optics II\nby
Kamuran Saygılı (İstanbul University) as part of Yeditepe Mathematics
Seminars\n\n\nAbstract\nOutline of a course: Introduction to Mathematical
Optics.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carlos Segovia González (Universidad Nacional Autónoma de Méxic
o)
DTSTART:20221028T130000Z
DTEND:20221028T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/55
DESCRIPTION:Title: Extension of free actions over surfaces\nby Carlos S
egovia González (Universidad Nacional Autónoma de México) as part of Ye
ditepe Mathematics Seminars\n\n\nAbstract\nOriented\, nonoriented and unit
ary bordism have certain module structures. We are interested in the unita
ry case which is a free module over the integers with even degrees. In the
case of equivariant unitary bordism for a compact Lie group\, it has been
shown that for certain cases\, we have a structure of free module (with r
espect to the usual unitary bordism) with generators in even degrees. Just
to mention\, Landweber proved the case of cyclic groups\, Stong-Ossa the
abelian groups\, Löffer-Comezaña for compact abelian Lie groups and ther
e are some proofs for metacyclic groups. The general case is known as the
unitary evenness conjecture (UEC). This conjecture will imply that in equi
variant bordism there is not torsion. A particular case will be that all f
ree action of a finite group over a compact oriented surface “always”
extends to a non-necessarily free action over a 3-manifold. In this talk w
e will see a counterexample that this is not always the case\, which gives
a counterexample of (UEC). A complete obstruction is given by the quotien
t of the 2-homology H_2(G) by the toral classes\, known as the Bogomolov m
ultiplier. The firs counterexample published is a group of order 3^5.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Laurence John Barker (Bilkent University)
DTSTART:20221209T113000Z
DTEND:20221209T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/56
DESCRIPTION:Title: The Puig category of a block and conjectural isomorphism
invariance of the multiplicities of the objects\nby Laurence John Bar
ker (Bilkent University) as part of Yeditepe Mathematics Seminars\n\n\nAbs
tract\nA modular group algebra decomposes as a sum of algebras called bloc
k algebras. The group acts as automorphisms on each block algebra. Reducin
g $p$-locally\, we pass to a smaller algebra called an almost-source algeb
ra\, upon which a p-subgroup called the defect group acts as automorphisms
. Three measures of the complexity of the block are\,firstly\, the defect
group itself\, secondly a finite category called the fusion system\,thirdl
y a somewhat larger finite category called the Puig category. Each object
of the Puig category comes with an associated multiplicity. We conjecture
that those multiplicities are invariant under the action of the fusion sys
tem. The conjecture has implications concerning the action of the defect g
roup on a permuted basis of the almost-source algebra. By Clifford theory\
, the conjecture holds when the given group is p-solvable. This work is jo
int with Matthew Gelvin.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pelin Ayşe Gökgöz (Yeditepe University)
DTSTART:20221202T113000Z
DTEND:20221202T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/57
DESCRIPTION:Title: Schwarz Problem in the Complex Plane\nby Pelin Ayşe
Gökgöz (Yeditepe University) as part of Yeditepe Mathematics Seminars\n
\n\nAbstract\nIn this talk\, we investigate the Schwarz problem in a ring
domain. We start with derivation of\nthe unique solution of the Schwarz pr
oblem for inhomogeneous Cauchy-Riemann equations and\ngeneralized Beltrami
equations. Next\, we extend the discussion to higher-order Cauchy-Riemann
\nequations and higher-order linear equations employing the properties of
higher-order operators.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yusuf Barış Kartal (University of Edinburgh)
DTSTART:20221216T113000Z
DTEND:20221216T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/58
DESCRIPTION:Title: Frobenius operators in symplectic topology\nby Yusuf
Barış Kartal (University of Edinburgh) as part of Yeditepe Mathematics
Seminars\n\n\nAbstract\nGiven prime p\, one can define Frobenius operators
on the commutative rings of characteristic p. This notion has generalizat
ions in a larger class of rings and even in topological spaces and spectra
. Spectra with circle actions and Frobenius operators are called cyclotomi
c spectra. A simple example is the free loop space. Major examples arise i
n algebraic and arithmetic geometry\, as topological Hochschild homology o
f rings and categories\, and many applications to these fields are found.
By mirror symmetry\, it is natural to expect the cyclotomic spectra to ari
se in symplectic topology. In this talk\, we will explain how to obtain cy
clotomic spectra using holomorphic cylinders in symplectic manifolds\, i.e
. by using Hamiltonian Floer theory. Joint work in progress with Laurent C
ote.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Burcu Silindir Yantır (Dokuz Eylül University)
DTSTART:20230317T113000Z
DTEND:20230317T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/59
DESCRIPTION:Title: Generalized discrete polynomials and applications\nb
y Burcu Silindir Yantır (Dokuz Eylül University) as part of Yeditepe Mat
hematics Seminars\n\n\nAbstract\nAlthough the calculus and the theory of d
ifference/differential equations have been deeply analyzed since the disco
very of time scales\, the study on a general time scale may have deficienc
ies and inapplicabilities even in some elementary subjects such as polynom
ials\, exponential functions\, Taylor series. To overcome these deficienci
es\, in this talk\, we present two approaches which unify and extend discr
ete time scales. First approach is based on the study of a special time sc
ale\, namely $(q\,h)$-time scale. We briefly introduce the calculus on del
ta and nabla $(q\,h)$-time scales. As an application\, we focus on $(q\,h)
$-analogue of Bessel equation and Bessel function which reduce $h$-\, $q$-
and ordinary Bessel equations and functions under proper limits. Furtherm
ore\, we present a second approach which is based on the construction of a
new time scale\, namely $\\alpha$-time scale. For this purpose\, we offer
a weighted jump operator $\\alpha$\, which generates the $\\alpha$-time s
cale\, $\\alpha$-derivative and $\\alpha$-polynomials.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yusuf Ünlü (Yeditepe University)
DTSTART:20221118T113000Z
DTEND:20221118T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/60
DESCRIPTION:Title: Compactifications of a Tychonoff space\nby Yusuf Ün
lü (Yeditepe University) as part of Yeditepe Mathematics Seminars\n\nAbst
ract: TBA\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:İlhan İkeda (Boğaziçi Üniversity)
DTSTART:20230609T093000Z
DTEND:20230609T103000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/61
DESCRIPTION:Title: Dictionary of Gröthendieck and automorphic representati
ons\nby İlhan İkeda (Boğaziçi Üniversity) as part of Yeditepe Mat
hematics Seminars\n\n\nAbstract\nIn the first part of our talk\, we shall
review Gröthendieck's "function-sheaf dictionary"\, and in the second par
t\, we shall discuss how this dictionary is used in\nthe Langlands recipro
city principle.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atabey Kaygun (İstanbul Technical University)
DTSTART:20230407T113000Z
DTEND:20230407T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/63
DESCRIPTION:Title: Extending Dold-Kan Theorem to Crossed Simplicial Groups<
/a>\nby Atabey Kaygun (İstanbul Technical University) as part of Yeditepe
Mathematics Seminars\n\n\nAbstract\nThe Dold-Kan Theorem is a statement a
bout the equivalence between the category of simplicial objects and the ca
tegory of chain complexes over an abelian category\, after certain natural
localizations. This equivalence is a Quillen equivalence\, with different
restricted versions of it appearing in literature. In this talk\, we will
explore an extension to the Dold-Kan equivalence by replacing the simplic
ial category with a crossed simplicial group. Crossed simplicial groups ar
e obtained from the simplicial category through a bicrossed product betwee
n the simplicial category and certain collections of (finite) groups. Conn
es' cyclic category being an example of this construction. While previous
attempts to extend the Dold-Kan to the Connes' cyclic category and beyond
involved constructing artificial categories in place of the category of dg
-objects over an abelian category\, we will pursue a new approach in this
talk. Specifically\, we will show that the Dold-Kan result can be reformul
ated using certain induction and restriction functors\, providing a clear
path for a natural extension of the Dold-Kan to crossed simplicial groups
when the groups used are all finite. This is an ongoing joint research pro
ject with my PhD student\, Haydar Can Kaya.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yusuf Civan (Süleyman Demirel Üniversitesi)
DTSTART:20230505T113000Z
DTEND:20230505T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/64
DESCRIPTION:Title: Nerves\, minors and coloring of graphs\nby Yusuf Civ
an (Süleyman Demirel Üniversitesi) as part of Yeditepe Mathematics Semin
ars\n\nLecture held in Yeditepe Math. Department Seminar Room.\n\nAbstract
\nA recent work of Holmsen et al. provides a topological method for detect
ing clique minors in graphs. They conjecture that the homological dimensio
n of (nerves of) connected covers completely detects clique minors. I will
explain in detail how this approach works\, and show that if it is true\,
their conjecture is almost equivalent to the Hadwiger conjecture. I will
provide a counterpart of this conjecture in the language of bipartite grap
hs\, and verify a relaxed version.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hasan Gümral (Yeditepe University)
DTSTART:20230512T113000Z
DTEND:20230512T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/65
DESCRIPTION:Title: Tulczyjew Symplectic Spaces for Displacement and Canonic
al Mappings\nby Hasan Gümral (Yeditepe University) as part of Yeditep
e Mathematics Seminars\n\n\nAbstract\nGiven a finite dimensional manifold
$Q$\, the cotangent bundle $(T^* Q\, \\omega)$ is symplectic. Let $M = \\{
\\xi : T ^*Q \\to Q \\}$ and $G =\\{ \\phi : T^*Q\\to T^*Q | \\phi^*\\ome
ga =\\omega\\} $ be manifolds of displacement and canonical mappings\, res
pectively. $G$ is a Lie group and bundles over $G$ admit global trivializa
tions. The embedding $G\\hookrightarrow T^*M$ is Lagrangian\, though\, not
with canonical two-form. It follows that the Tulczyjew symplectic spaces
$TT^* M$ and $T T^*G$ are fiberwise isomorphic. This result is key to es
tablishing relations among different formulations of plasma dynamics in th
e Tulczyjew's geometric framework for Legendre transformation.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mehmet Akif Erdal (Yeditepe Univesity)
DTSTART:20190315T113000Z
DTEND:20190315T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/66
DESCRIPTION:Title: Equivariant model structures via orbits\nby Mehmet A
kif Erdal (Yeditepe Univesity) as part of Yeditepe Mathematics Seminars\n\
nLecture held in Seminar Room.\n\nAbstract\nFor a given group $G$ the cate
gory of $G$-spaces and $G$-equivariant maps admits a model structure in wh
ich the weak equivalences and fibrations are defined as $G$-maps that indu
ce weak equivalences and fibrations on $H$-fixed point spaces for every $H
\\leq G$. In this model category the fibrant-cofibrant objects are $G$-$C
W$-complexes. A weak equivalence between such objects is a $G$-homotopy eq
uivalence\; and thus\, induces weak equivalences on $H$-orbits for every $
H \\leq G$. The converse\, however\, is not true. It is natural to ask wha
t is needed for $X\,Y$ so that maps $f:X\\to Y$ inducing weak equivalences
on $H$-orbits also induce weak equivalences on $H$-fixed point spaces. To
provide an answer\, we construct a new model structure on the category of
$G$-spaces in which the weak equivalences and cofibrations are defined as
maps inducing weak equivalences and cofibrations on $H$-orbits for each $
H \\leq G$. We show that a weak equivalence between objects that are fibra
nt in this new model structure is a weak equivalence in the fixed point mo
del structure. This is a joint work with Aslı Güçlükan İlhan.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Adalet Çengel (Boğaziçi University)
DTSTART:20190405T113000Z
DTEND:20190405T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/67
DESCRIPTION:Title: Signatures of Lefschetz fibrations\nby Adalet Çenge
l (Boğaziçi University) as part of Yeditepe Mathematics Seminars\n\nLect
ure held in Seminar Room.\n\nAbstract\nDonaldson has shown that a closed s
ymplectic $4$-manifold up to blow-up is equivalent to that of a Lefschetz
fibration over the $2$-sphere. The topology of the total space of a Lefsch
etz fibration is completely determined by its monodromy representation whi
ch is a product of positive Dehn twists.\n\nWe give an algorithm to comput
e signature of a given Lefschetz fibration over $2$-disk by using its mono
dromy factorization. Our main tool will be Wall’s non-additivity formula
applied to what we call partial fiber sum decomposition of a Lefschetz fi
bration over disk. We show that our algorithm works for Lefschetz fibratio
ns with regular fiber having nonempty boundary. When the regular fibers ar
e closed\, it is a reformulation of Burak Özbağcı’s algorithm which i
s described in his Ph.D. thesis for the calculation of signatures of Lefsc
hetz fibrations. This is a joint work with Çağrı Karakurt.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Özgün Ünlü (Bilkent University)
DTSTART:20190412T113000Z
DTEND:20190412T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/68
DESCRIPTION:Title: Free Group Actions on Products of Spheres\nby Özgü
n Ünlü (Bilkent University) as part of Yeditepe Mathematics Seminars\n\n
Lecture held in Seminar Room.\n\nAbstract\nWe will first discuss some know
n conditions on groups that can\nact freely on certain products of spheres
. Then we will review some\nknown conjectures about free group actions on
products of spheres.\nFinally\, we will talk about some recently employed
methods for\nconstructing free group actions on products of spheres.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ayşe Borat (Bursa Technical University)
DTSTART:20190426T113000Z
DTEND:20190426T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/69
DESCRIPTION:Title: Directed topological complexity of spheres\nby Ayşe
Borat (Bursa Technical University) as part of Yeditepe Mathematics Semina
rs\n\nLecture held in Seminar Room.\n\nAbstract\nTopological complexity is
a homotopy invariant which measures how far a space away from admitting a
motion planning algorithm [2]. A new variant of topological complexity gi
ven through directed paths is introduced by Goubault\, Sagnier and Farber
in [3]. This new concept is useful for classifying directed spaces. \n\nI
n this talk\, I will give a brief introduction to usual topological comple
xity and directed topological complexity\, and I will discuss directed top
ological complexity of directed $n$-spheres [1]. This is a joint work with
Mark Grant.\n \nBibliography\n\n[1] A. Borat\, M. Grant\, Directed topolo
gical complexity of spheres\, submitted. \\href{https://arxiv.org/pdf/1810
.00339.pdf}{arXiv:1810.00339}. \n\n[2] M. Farber\, Topological complexity
of motion planning\, Discrete Comput. Geom. 29 (2003)\, no. 2\, 211—221.
\n\n[3] E. Goubault\, A. Sagnier\, M. Farber\, Directed topological compl
exity\, submitted. \\href{https://arxiv.org/pdf/1812.09382.pdf}{arXiv:1812
.09382}. \n\\end{thebibliography}}\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rıza Seçkin Adalı (University of Oslo)
DTSTART:20190524T113000Z
DTEND:20190524T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/70
DESCRIPTION:Title: Singularities of Restriction Varieties in $OG(k\,n)$
\nby Rıza Seçkin Adalı (University of Oslo) as part of Yeditepe Mathema
tics Seminars\n\n\nAbstract\nRestriction varieties in the orthogonal Grass
mannian are subvarieties of $OG(k\, n)$ defined by rank conditions given b
y a flag that is not necessarily isotropic with respect to the relevant sy
mmetric bilinear form. In particular orthogonal Schubert varieties are exa
mples of restriction varieties. In this talk\, I will describe a resolutio
n of singularities for restriction varieties which is inspired by the Bott
-Samelson/Zelevinsky resolution and describe their singular locus. I will
also discuss the relation between the singular locus and the image of the
resolution of singularities.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Olcay Coşkun (Boğaziçi University)
DTSTART:20191011T113000Z
DTEND:20191011T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/71
DESCRIPTION:Title: Gluing biset functors\nby Olcay Coşkun (Boğaziçi
University) as part of Yeditepe Mathematics Seminars\n\nLecture held in Se
minar Room.\n\nAbstract\nWe develop an obstruction theory for the existenc
e and uniqueness of a solution to the gluing problem for a biset functor.
The obstruction groups for this theory are reduced cohomology groups of a
category of sections. Using this obstruction theory\, we calculate the obs
truction group for the Dade group of a $p$-group when $p$ is odd. This is
a joint work with Ergün Yalçın.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Serap Öztop Kaptanoğlu (İstanbul University)
DTSTART:20191018T113000Z
DTEND:20191018T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/72
DESCRIPTION:Title: A Survey of Orlicz Algebras on Locally Compact Groups\nby Serap Öztop Kaptanoğlu (İstanbul University) as part of Yeditepe
Mathematics Seminars\n\nLecture held in Seminar Room.\n\nAbstract\nLet $G$
be a locally compact group\, $\\Phi$ be a Young\nfunction\, and denote by
$L^\\Phi(G)$ the associated Orlicz space.\nThis talk is a survey of resul
ts on Banach algebra and Banach module structures of Orlicz spaces on $G$
that we have obtained recently in collaboration with our colleagues. We pr
esent conditions for an Orlicz algebra to be Arens regular. We investigate
their cohomological properties such as amenability. We determine when an
Orlicz algebra is an operator algebra. Our approach can be applied to a va
st variety of cases and extend the results in the classical situation. \n\
nThis presentation is based on joint works with Ebrahim Samei and Varvara
Shepelska of University of Saskatchewan\, Canada.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hakkı Turgay Kaptanoğlu (Bilkent University)
DTSTART:20191025T113000Z
DTEND:20191025T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/73
DESCRIPTION:Title: Shift Operators on Hilbert Harmonic Function Spaces\
nby Hakkı Turgay Kaptanoğlu (Bilkent University) as part of Yeditepe Mat
hematics Seminars\n\nLecture held in Seminar Room.\n\nAbstract\nIn an atte
mpt to identify the harmonic Drury-Arveson space\, we introduce and inves
tigate large families of reproducing kernel Hilbert spaces of harmonic fun
ctions the unit ball of $\\mathbb R^n$. Using zonal harmonics\, we define
and develop basic properties of shift operators and their adjoints in the
harmonic setting. We prove a dilation result for the shift operators on ha
rmonic spaces that are row contractions. As a consequence\, we show that t
he norm of one of our spaces Ğ is maximal among those spaces on which the
shift operator is a row contraction. We also show the maximality of the o
perator norm of the shift on Ğ among contractive Hilbert norms on harmoni
c polynomials. We then describe the progress towards a von Neumann inequal
ity for harmonic polynomials and a tuple of commuting operators on harmoni
c spaces that are row contractions and belong to a certain class.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:İpek Tuvay (Mimar Sinan Fine Arts University)
DTSTART:20191108T113000Z
DTEND:20191108T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/74
DESCRIPTION:Title: An application of Baer-Suzuki Theorem to modular represe
ntation theory\nby İpek Tuvay (Mimar Sinan Fine Arts University) as p
art of Yeditepe Mathematics Seminars\n\nLecture held in Seminar Room.\n\nA
bstract\nThe Baer-Suzuki Theorem states that if $p$ is a prime\, $x$ is a
$p$-element in a finite group $G$ and $$ is a $p$-group for every
element $g$ of $G$\, then the conjugacy class of $x$ in $G$ lies in a nor
mal $p$-subgroup of $G$. In this talk\, we present a very nice application
of this theorem and using this we show that for a finite group $G$ with a
semidihedral subgroup $P$\, the Scott module $Sc(G\,P)$ is Brauer indecom
posable. This is a joint work with Shigeo Koshitani.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yasemin Kara (Boğaziçi University)
DTSTART:20191129T113000Z
DTEND:20191129T123000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/75
DESCRIPTION:Title: Asymptotic Generalized Fermat’s Last Theorem over Numb
er Fields\nby Yasemin Kara (Boğaziçi University) as part of Yeditepe
Mathematics Seminars\n\nLecture held in Seminar Room.\n\nAbstract\nRecent
work of Freitas and Siksek showed that an asymptotic version of Fermat’
s Last Theorem (FLT) holds for many totally real fields. This\nresult was
extended by Deconinck to the generalized Fermat equation of\nthe form $Ax^
p + By^p + Cz^p = 0$\, where $A\, B\, C$ are odd integers belonging\nto a
totally real field. Later Şengün and Siksek showed that the asymptotic F
LT holds over number fields assuming two standard modularity\nconjectures.
\n\nIn this work\, combining their techniques we show that the generalized
\nFermat’s Last Theorem (GFLT) holds over number fields asymptotically\n
assuming the standard conjectures. We also give three results which show\n
the existence of families of number fields on which asymptotic versions of
\nFLT or GFLT hold. In particular\, we prove that the asymptotic GFLT\nhol
ds for a set of imaginary quadratic number fields of density $5/6$.\n\nThi
s is a joint work with Ekin Özman.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ekin Özman (Boğaziçi University)
DTSTART:20240419T100000Z
DTEND:20240419T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/76
DESCRIPTION:Title: Modular Curves\, Rational Points and Diophantine Equatio
ns\nby Ekin Özman (Boğaziçi University) as part of Yeditepe Mathema
tics Seminars\n\n\nAbstract\nExploring solutions to Diophantine equations
over a number field stands as a key challenge in number theory. Using the
modular techniques employed by Wiles in proving Fermat’s last theorem an
d its extensions\, we can extend our ability to solve various Diophantine
equations. Additionally\, understanding points on the classical modular cu
rve contributes significantly to this methodology. In this presentation\,
I will address specific questions and share results that have emerged from
this area of study.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mahmut Elbistan (İstanbul Bilgi University)
DTSTART:20240503T100000Z
DTEND:20240503T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/77
DESCRIPTION:Title: Various disguises of the Pais-Uhlenbeck oscillator\n
by Mahmut Elbistan (İstanbul Bilgi University) as part of Yeditepe Mathem
atics Seminars\n\n\nAbstract\nPais-Uhlenbeck oscillator is one of the best
known higher derivative models. In this talk\, I will discuss realization
s of this mechanical model in physical setups with second order equations
of motion. I will explicitly show that dynamics in some certain gravitatio
nal waves in 4 dimensions and Penning trap in 3 dimensions are governed by
1-dimensional Pais-Uhlenbeck oscillator.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kadri İlker Berktav (Bilkent University)
DTSTART:20240329T100000Z
DTEND:20240329T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/78
DESCRIPTION:Title: Symplectic and contact structures on derived stacks\
nby Kadri İlker Berktav (Bilkent University) as part of Yeditepe Mathemat
ics Seminars\n\n\nAbstract\nIn this talk\, we outline our program for the
development of shifted contact structures in the context of derived algebr
aic geometry. We start by recalling some key notions and results from deri
ved algebraic/symplectic geometry. Next\, we discuss shifted contact struc
tures on derived Artin stacks and report our results on their local theory
and sample constructions.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emine Yıldırım Kaygun (University of Leeds)
DTSTART:20240524T100000Z
DTEND:20240524T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/79
DESCRIPTION:Title: From Triangulations to Friezes and Cluster Algebras\
nby Emine Yıldırım Kaygun (University of Leeds) as part of Yeditepe Mat
hematics Seminars\n\n\nAbstract\nIn this talk\, we first talk about some c
ombinatorics on the triangulated surfaces and then show interesting connec
tions to up-to-date research topics like Friezes and Cluster algebras. Thi
s presentation will include some collaborative work with K. Baur\, L. Bitt
man\, E. Gunawan\, and G. Todorov. If time permits\, we will also explore
more on computational aspects which is another collaborative work with E.
Kantarcı Oğuz.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dilara Karslıoğlu (Yeditepe University)
DTSTART:20240517T100000Z
DTEND:20240517T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/80
DESCRIPTION:Title: On the Blow-up Solutions to a Fourth-Order Pseudo-Parabo
lic Equation with Gradient Non-Linearity\nby Dilara Karslıoğlu (Yedi
tepe University) as part of Yeditepe Mathematics Seminars\n\nLecture held
in Mathematics&Physics Seminar Room.\n\nAbstract\nIn this study\, the init
ial and periodic boundary value problem was solved for the following four
th-order pseudo-parabolic equation with gradient non-linearity and pseudo
term \n $$ u_t-a\\Delta u_t-\\Delta u+\\Delta^2u=-\\nabla\\cdot(|\\nabla u
|^{p-2}\\nabla u)$$\nwhere $a\\ge 0$. Local existence-uniqueness result fo
r mild solutions was found for any initial data in $L^2(\\Omega)$. In add
ition\, the existence of blow-up solutions was proved and a lower bound fo
r the blow-up time was obtained.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/80/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Deniz Karlı (Işık University)
DTSTART:20241218T103000Z
DTEND:20241218T113000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/82
DESCRIPTION:Title: Stochastic Analysis For Singular Integral Operators and
Fractional Derivatives\nby Deniz Karlı (Işık University) as part o
f Yeditepe Mathematics Seminars\n\nLecture held in Yeditepe Math Seminar R
oom.\n\nAbstract\nOn the cross-section of Probability Theory and Analysis\
, singular integral operators and related boundedness problems of Analysis
are studied by means of stochastic processes. One of the main problems is
to determine a general class of multipliers and so the bounded operators
on function spaces. In this talk\, we use a discontinuous process\, namely
a symmetric stable process\, to show boundedness results of extended vers
ions of classical singular integral operators which arises from classical
multipliers. In the first part of our talk\, we will discuss how one can b
uild the connection between integral operators in Classical Analysis and S
tochastic Analysis. We will introduce versions of intermediate operators a
ppearing in the Littlewood-Paley Theory and show recent boundedness result
s. The second part of our talk will present the relation between these new
operators and fractional derivative in its integral form and we discuss m
ultipliers defined in terms of fractional derivatives. We show an extended
class of multipliers obtained through a new version of Mikhlin Multiplier
Theorem and explain why classical multipliers form a sublass of this new
extended class of multipliers.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/82/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Devrim Bilgili (University of Florida)
DTSTART:20241204T130000Z
DTEND:20241204T140000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/83
DESCRIPTION:Title: Size and shape analysis of silica (SiO2) and gold (Au) n
anoparticles\nby Devrim Bilgili (University of Florida) as part of Yed
itepe Mathematics Seminars\n\n\nAbstract\nIn nanotechnology\, the size and
shape control of nanoparticles is crucial as their properties are highly
dependent on their morphology. This obliges researchers to work on obtaini
ng uniform size and shape distribution in synthesized particles so that th
eir electrical\, optical\, and magnetic properties remain uniform within t
he same batch. This brings the problem of how to quantify the shape and si
ze of nanoparticles in the most accurate way. The most common way to deter
mine size distribution is using UV-vis spectrometry\; however\, this metho
d disregards the existence of agglomerated particles and may sometimes giv
e an incorrect measurement. Therefore a technique that can obtain this dat
a directly from the transmission electron microscopy (TEM) images of parti
cles would be more reliable as it would capture data for every single part
icle in the batch. In a classical statistical sense\, our interest is the
shape and size distribution of nanoparticles. In this paper\, we quantify
the size and shape of nanoparticles using the statistical techniques appli
ed on TEM images of particles: Functional Data and Shape Analysis. By usin
g this shape theory we obtain the geodesic distances not only between the
particles but also among the frames. We further cluster the nanoparticles
in terms of their similarities. We want to emphasize the importance of the
deformation and how it is done from one nanoparticle onto another.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tekin Dereli (Koç University)
DTSTART:20241127T100000Z
DTEND:20241127T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/86
DESCRIPTION:Title: Electromagnetic Hertz potentials and the Cabibbo-Ferrari
theory of magnetic monopoles\nby Tekin Dereli (Koç University) as pa
rt of Yeditepe Mathematics Seminars\n\nLecture held in Yeditepe Math Semin
ar Room.\n\nAbstract\nAfter a brief review of differential geometric gauge
aspects of Maxwell equations I am going to introduce Hertz potentials for
electro-magnetic fields. This formalism allows for establishing a manifes
t duality invariance of the Maxwell-Lorentz electrodynamics. As an applica
tion I will discuss the Cabibbo-Ferrari theory of magnetic monopoles.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/86/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Halit Şevki Aslan (University of São Paulo)
DTSTART:20241030T100000Z
DTEND:20241030T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/87
DESCRIPTION:Title: $L^p-L^q$ estimates for solutions to the plate equation
with mass term\nby Halit Şevki Aslan (University of São Paulo) as pa
rt of Yeditepe Mathematics Seminars\n\n\nAbstract\nIn this talk\, we are g
oing to study the following Cauchy problem for the plate equation with mas
s term:\n$$u_{tt} + \\Delta^2u + u = 0\\ \\text{if} \\ (t\,x)\\in (0\,\\i
nfty)\\times \\mathbb{R}^n$$\n $$u(0\,x)=u_0(x)\\ \\ u_t(0\,x)=u_1(x)\\ \\
\\text{if} \\ x\\in \\mathbb{R}^n.$$\nOur goal is to derive $L^p-L^q$ es
timates for the solutions to problem \\eqref{eq_1} in the full range $1 \\
leq p \\leq q \\leq \\infty$. After that\, we study the associated semilin
ear model with power non-linearity $|u|^{\\alpha}$ with $\\alpha>1$\, wher
e we apply the derived $L^p-L^q$ estimates in the analysis of local (in ti
me) existence of solution and for the global (in time) small data solution
s.\n\nThe results of this talk are based on collaboration with} \n\n Alexa
ndre A. Junior (University of S\\~ao Paulo\, Ribeir\\~ao Preto\, Brazil)\,
\n\nMarcelo R. Ebert (University of S\\~ao Paulo\, Ribeir\\~ao Preto\, Bra
zil)\,\n\nAntonio Lagioia (University of Bari\, Italy).\n\nReferences\n\n[
1] M. D'Abbicco\, M.R. Ebert\, $L^p-L^q$ estimates for a parameter-depende
nt multiplier with oscillatory and diffusive components. J. Math. Anal. Ap
pl. {504} (2021).\n\n\n[2] M. Ikeda\, T. Inui\, A remark on non-existence
results for the semi-linear damped Klein-Gordon equations. RIMS Kôkyûrok
u Bessatsu B56\, (2016)\, 11--30.\n\n[3] B. Marshall\, W. Strauss\, S. Wai
nger\, $L^p-L^q$ estimates for the Klein-Gordon equation. J. Math. Pures A
ppl. 59. (1980) 417--440.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sultan Sütlü (Acıbadem University)
DTSTART:20241225T100000Z
DTEND:20241225T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/88
DESCRIPTION:Title: A Stability Study by Routh-Hurwitz Criterion and Gershgo
rin Circles for Infectious Diseases\nby Sultan Sütlü (Acıbadem Univ
ersity) as part of Yeditepe Mathematics Seminars\n\nLecture held in Yedite
pe Math Seminar Room.\n\nAbstract\nThe mathematical theory of infectious d
iseases and epidemics has always been interesting for many branches of sci
ence. In this talk\, we present the stabilization problem on a model for C
ovid-19 by using the Routh-Hurwitz criterion and Gershgorin circles. Using
Routh-Hurwitz criterion\, we prove the necessity of unstability and stabi
lity conditions for the model that we extend from an existing one. We give
the necessary conditions for stability on this model by using the Gershgo
rin Circle Theorem and give examples.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Başak Küçük (University of Göttingen)
DTSTART:20250418T100000Z
DTEND:20250418T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/89
DESCRIPTION:Title: Homotopical Obstruction to Fixed Points of Equivariant M
aps\nby Başak Küçük (University of Göttingen) as part of Yeditepe
Mathematics Seminars\n\n\nAbstract\nThe Lefschetz number provides an obst
ruction theory for the classical fixed point problem\, which asks whether
a given map can be homotoped to one without fixed points. According to the
Lefschetz fixed point theorem\, if a self-map on a compact triangulable s
pace has no fixed points\, then its Lefschetz number must be zero. However
\, the converse does not necessarily hold. A more refined invariant\, the
Nielsen number\, provides a converse under a certain dimension condition.\
nIn this talk\, we explore a more general version of the fixed point probl
em in the equivariant setting. Klein and Williams developed an obstruction
theory for equivariant fixed points [2\, Theorem H]. An alternative appro
ach\, based on a collection of Nielsen numbers\, was proposed by Fadell an
d Wong [1]. It was stated as a conjecture in [2] whether these Nielsen num
bers can be computed from the Klein-Williams invariant. We will begin by d
efining the Nielsen number and then discuss the construction of the Klein-
Williams invariant. The talk will conclude with a focus on the conjecture
in [2] and present results addressing this question.\n\nReferences\n\n[1]
Edward Fadell and Peter Wong. On deforming G-maps to be fixed point free.
Pacific Journal of Mathematics\, 132(2):277 – 281\, 1988.\n\n[2] John R.
Klein and Bruce Williams. Homotopical intersection theory\, II: Equivaria
nce. Math. Z.\, 264(4):849–880.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Orendain (Case Western Reserve University)
DTSTART:20250516T150000Z
DTEND:20250516T160000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/92
DESCRIPTION:Title: Compositional Quantum Field Theory\nby Juan Orendain
(Case Western Reserve University) as part of Yeditepe Mathematics Seminar
s\n\n\nAbstract\nCompositional Quantum Field Theory (CQFT) is an axiomatic
framework for reasoning about Quantum Field Theory\, based on the princip
les of locality and compositionality. The first ingredient of CQFT is a sp
acetime gluing syntax based on gluing maps and gluing diagrams. I will pre
sent this in detail. Once this is set up\, I will introduce CQFT axiomatic
ally\, and I will show how to recast these axioms as a type of functorial
semantics translating our spacetime syntax into Hilbert spaces\, using alg
ebras over *-operads and constrained maps between them. Finally\, we will
investigate how in CQFT in dimension 2\, e.g. in 2 dimensional Quantum Yan
g-Mills theory\, our functorial semantics viewpoint allows for certain str
uctures to emerge from first principles. An example of this is the structu
re of cyclic\, involutive A_oo-algebra on the state space of the interval.
\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sema Salur (University of Rochester)
DTSTART:20250509T100000Z
DTEND:20250509T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/93
DESCRIPTION:Title: Manifolds with Special Holonomy\nby Sema Salur (Univ
ersity of Rochester) as part of Yeditepe Mathematics Seminars\n\n\nAbstrac
t\nManifolds with special holonomy\, such as Calabi–Yau and G₂\nmanifo
lds\, are Riemannian manifolds whose holonomy groups are\ncontained in SU(
n) (for n = 2m) and the exceptional Lie group G₂ (for\nn = 7)\, respecti
vely. These spaces arise naturally as Ricci-flat\nexamples in differential
geometry and play a central role in\ntheoretical physics\, particularly i
n M-theory compactifications.\nM-theory\, often described as a candidate f
or a "theory of\neverything''\, aims to unify the fundamental forces of na
ture:\nelectromagnetism\, gravity\, and the strong and weak nuclear forces
.\n\nCalibrated submanifolds within Calabi–Yau and G₂ manifolds are vo
lume\nminimizing in their homology classes\, and their moduli spaces have\
ndeep applications in geometry\, topology\, and physics. In this talk\, we
\nwill begin with a brief introduction to Calabi–Yau and G₂ manifolds\
,\nand then report on recent research exploring the rich interplay\nbetwee
n symplectic\, contact\, and calibrated structures in manifolds\nwith spec
ial holonomy.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Justyna Ogorzały (Military University of Technology of Warsaw)
DTSTART:20250704T100000Z
DTEND:20250704T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/94
DESCRIPTION:Title: Variational-Hemivariational Inequalities with Applicatio
ns to Contact Mechanics\nby Justyna Ogorzały (Military University of
Technology of Warsaw) as part of Yeditepe Mathematics Seminars\n\n\nAbstra
ct\nWe will present the existence and uniqueness results for a class of ab
stract nonlinear variational-hemivariational inequalities. Next\, we will
present applications of the abstract results into the analysis of concrete
contact problems.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Orsan Kılıçer (Texas A&M University)
DTSTART:20250815T100000Z
DTEND:20250815T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/95
DESCRIPTION:Title: Higher Order FEM for Surface Stokes Problems\nby Ors
an Kılıçer (Texas A&M University) as part of Yeditepe Mathematics Semin
ars\n\n\nAbstract\nThis research focuses on developing a higher-order fini
te element method for solving the Surface Stokes Problem. Finite element m
ethods face challenges due to the possible ill-posedness caused by Killing
fields\, and an $H^1$-conforming method cannot be constructed for merely
$C^0$ discrete surfaces.\n\nTo address these difficulties\, this work intr
oduces a mass term into both the weak and strong formulations and employs
an H(div)-conforming $BDM_k - P_{k-1}$ pair for velocity and pressure whil
e using Lagrange interpolation for higher-order surface approximations.\n\
nThe study analyzes discrete Korn-type inequalities\, discrete inf-sup con
ditions\, norm equivalencies on discrete and continuous surfaces\, and bot
h geometric and Galerkin errors associated with the proposed method.\n\nTh
eoretical error estimates demonstrate sharp energy error convergence for v
elocity and $L^2$ error convergence for pressure\, which align well with n
umerical results. However\, in theory\, a suboptimal $L^2$ velocity error
estimate is observed due to geometric error limitations.\n\nOverall\, this
research provides a stable finite element framework for solving the Surfa
ce Stokes Problem. The findings contribute to the numerical analysis of su
rface partial differential equations and offer a foundation for further im
provements in geometric error estimation.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Richard Gonzales (IHES - PUCP)
DTSTART:20250919T100000Z
DTEND:20250919T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/96
DESCRIPTION:Title: Equivariant cohomology of group embeddings\nby Richa
rd Gonzales (IHES - PUCP) as part of Yeditepe Mathematics Seminars\n\n\nAb
stract\nIn this talk I will describe how the symmetries of a variety (enco
ded via a group action) can be used to understand the geometry and topolog
y not only of the variety itself\, but also of higher structures defined o
n it\, like vector bundles or sheaves. The study of those structures that
are left invariant under the group action leads naturally to the notion of
equivariant cycles and related topological invariants (e.g. Chow groups).
Moreover\, in many cases of interest (e.g. group embeddings or compactifi
cations of reductive groups) these topological invariants can be read off
from a suitable combinatorial object\, like a graph or a fan\, leading to
nice combinatorial descriptions of the corresponding cohomology. In this t
alk I will describe how the symmetries of a variety (encoded via a group a
ction) can be used to understand the geometry and topology not only of the
variety itself\, but also of higher structures defined on it\, like vecto
r bundles or sheaves. The study of those structures that are left invarian
t under the group action leads naturally to the notion of equivariant cycl
es and related topological invariants (e.g. Chow groups). Moreover\, in ma
ny cases of interest (e.g. group embeddings or compactifications of reduct
ive groups) these topological invariants can be read off from a suitable c
ombinatorial object\, like a graph or a fan\, leading to nice combinatoria
l descriptions of the corresponding cohomology.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yıldıray Ozan (METU)
DTSTART:20251212T100000Z
DTEND:20251212T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/97
DESCRIPTION:Title: Orientations of Vector Spaces and Manifolds\nby Yıl
dıray Ozan (METU) as part of Yeditepe Mathematics Seminars\n\nLecture hel
d in Yeditepe Math Seminar Room.\n\nAbstract\nIn this talk\, we will first
define an orientation of a real \nvector space. After introducing the nat
ural orientation of complex \nvector spaces\, we will discuss the orientat
ions of manifolds. In this \ncontext\, we will discuss the geometric conse
quences of the natural \norientations of complex manifolds. Finally\, we w
ill discuss the \ninability of the real projective plane\, the simplest ex
ample of an \nunorientable manifold\, to be embedded in three-dimensional
Euclidean \nspace. If time permits\, we will discuss a geometric consequen
ce of \nthis result.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/97/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Massimo Lanza de Cristoforis (Università degli Studi di Padova)
DTSTART:20251219T093000Z
DTEND:20251219T103000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/98
DESCRIPTION:Title: Representation theorems for nonvariational solutions of
the Helmholtz equation\nby Massimo Lanza de Cristoforis (Università
degli Studi di Padova) as part of Yeditepe Mathematics Seminars\n\n\nAbstr
act\nWe consider a bounded open subset $\\Omega$ of ${\\mathbb{R}}^n$ of c
lass $C^{1\,\\alpha}$ for some\n$\\alpha\\in]0\,1[$ and we plan to present
integral representation theorems for $\\alpha$-H\\"{o}lder continuous sol
utions of the Helmholtz equation in $\\Omega$ and in the exterior of $
\\Omega$\nthat may have an infinite Dirichlet integral around the boundary
of $\\Omega$. Thus for solutions that do not belong to the classical va
riational setting.\n\nSeminar will start at 12:30.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gönenç Onay (Galatasaray University)
DTSTART:20251107T100000Z
DTEND:20251107T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/99
DESCRIPTION:Title: Laurent Series in Positive Characteristic: Axiomatizatio
n Problems\nby Gönenç Onay (Galatasaray University) as part of Yedit
epe Mathematics Seminars\n\n\nAbstract\nLaurent Series in Positive Charact
eristic: Axiomatization Problems Valued fields combine algebraic and analy
tic structures through valuations. This talk focuses on axiomatization and
decidability problems for Laurent series fields in positive characteristi
c. After surveying classical results\, I will present my contributions on
valued fields equipped with endomorphisms—a natural framework in charact
eristic p where the Frobenius map provides a canonical self-endomorphism
—and discuss axiomatization challenges for the field of Laurent series o
ver the prime field of characteristic p (resp. over algebraically closed f
ields of characteristic p). The presentation will remain accessible to non
-specialists.\n\nYeditepe University Math-Physics Seminar Room\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/99/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Roghayeh Hafezieh (Gebze Technical University)
DTSTART:20251205T100000Z
DTEND:20251205T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/100
DESCRIPTION:Title: The solvability criterion for finite groups considering
vanishing classes\nby Roghayeh Hafezieh (Gebze Technical University)
as part of Yeditepe Mathematics Seminars\n\nLecture held in Yeditepe Math
Seminar Room.\n\nAbstract\nFor a finite group $G$\, an element is called a
vanishing element of $G$ if it is a zero of an irreducible character of $
G$\; otherwise\, it is called a non-vanishing element. Moreover\, the conj
ugacy class of an element is termed as a vanishing class if that element i
s a vanishing element. In this talk\, we present a solvability criterion w
ith respect to the set of vanishing class sizes.\n\nThe talk will be in cl
ass.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/100/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rüya Üster (İstanbul University)
DTSTART:20251128T100000Z
DTEND:20251128T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/101
DESCRIPTION:Title: Orlicz modülasyon uzayları ve pseudo-diferansiyel ope
ratörler\nby Rüya Üster (İstanbul University) as part of Yeditepe
Mathematics Seminars\n\n\nAbstract\nBu konuşmada pseudo-diferansiyel oper
atörlerin süreklilik özelliklerini Orlicz modülasyon uzaylarında ince
leyeceğiz. Orlicz modülasyon uzayları klasik Lebesgue modülasyon uzayl
arını da içerdi˘ginden elde ettiğimiz sonuçlar literatürde bilinen
sonuçları da kapsayacaktır.\n\nBu çalışma J.Toft\, N. Rana ve A. Gum
ber ile ortak araştırmanın ürünüdür\n\nPlease note that the talk wi
ll be in Turkish.\n
LOCATION:
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fatih Şirin (Haliç University)
DTSTART:20251114T100000Z
DTEND:20251114T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/102
DESCRIPTION:Title: Rubio de Francia Extrapolation: From Scalar to Matrix W
eighted Spaces\nby Fatih Şirin (Haliç University) as part of Yeditep
e Mathematics Seminars\n\n\nAbstract\nThe theory of weighted inequalities
is a foundational component of modern harmonic analysis. The Rubio de Fran
cia extrapolation theorem provides a powerful principle: the boundedness o
f an operator on a single weighted Lebesgue space for all Muckenhoupt weig
hts implies corresponding bounds on for every . This theorem offers a unif
ied framework for many classical estimates.\n\nIn this talk\, we will firs
t review the classical extrapolation theory in the scalar-\nweighted setti
ng\, highlighting the structure of weights and the role of the\nHardy–Li
ttlewood maximal operator. We then introduce the extension of extrapolatio
n methods to matrix weights\, where new geometric and analytic challenges
arise. The matrix-weighted framework allows us to study vector-valued oper
ators and yields broad applications to singular integral theory.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/102/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Murat Can Aşkaroğulları (İstanbul Technical University)
DTSTART:20260403T100000Z
DTEND:20260403T110000Z
DTSTAMP:20260405T171045Z
UID:7tepemathseminars/103
DESCRIPTION:Title: Leibniz PROP is a crossed presimplicial algebra\nby
Murat Can Aşkaroğulları (İstanbul Technical University) as part of Ye
ditepe Mathematics Seminars\n\nLecture held in Yeditepe Math Seminar Room.
\n\nAbstract\nLeibniz algebras\, introduced by Loday and Pirashvili [2]\,
are analogues of Lie algebras that are not skew-symmetric. Just as in the
Lie case\, Leibniz algebras are governed by an operad and can be modeled b
y an associated PROP [1].\n\nInspired by the Loday complex of a Leibniz al
gebra\, we define a new set of generators for the Leibniz PROP where spec
ific $(1\,k)$-shuffles are intrinsic to the generators. We prove that th
e Leibniz PROP is isomorphic as $\\Bbbk$-linear categories (not as monoida
l categories) to the symmetric crossed presimplicial algebra $\\Bbbk[(\\De
lta^+)^{op} \\mathbb{S}]$ where $\\Delta^+$ is the presimplicial category\
, but the distributive law between $(\\Delta^+)^{op}$ and the symmetric gr
oups $\\mathbb{S} = \\bigsqcup_{n\\geq 1} S_n$ is not the standard one.\n\
nIn establishing this result\, we also extend the standard distributive la
w between $\\Bbbk[(\\Delta^+)^{op}]$ and $\\Bbbk[\\mathbb{S}]$ to a distr
ibutive law between the nonsymmetric magmatic PROP and Artin's braid monoi
d $\\Bbbk[\\mathbb{B}]$ where $\\mathbb{B} = \\bigsqcup_{n\\geq 1} B_n$. F
urthermore\, our proof yields a description of the boundary maps on the Lo
day complex as alternating sums of partial boundary maps. \n\nThis is a jo
int work with Atabey Kaygun.\n\n\nReferences\n\n1. J.-L. Loday and B. Vall
ette\, Algebraic operads\, Grundlehren der mathematischen Wissenschaften\,
346\, 2012. \n\n2. J.-L. Loday and T. Pirashvili\, Universal enveloping a
lgebras of Leibniz algebras and (co)homology\, Mathematische Annalen\, 296
(1)\, 139--158\, 1993. \n\n3. J. Beck\, Distributive laws\, In: Sem. on T
riples and Categorical Homology Theory\, Lecture Notes in Math.\, No. 80\,
119--140\, 1969.\n
LOCATION:https://master.researchseminars.org/talk/7tepemathseminars/103/
END:VEVENT
END:VCALENDAR