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BEGIN:VEVENT
SUMMARY:Florian Eisele (University of Manchester)
DTSTART:20220117T140000Z
DTEND:20220117T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/1
DESCRIPTION:Title: Bijections of silting complexes and derived Picard groups\nby Flor
ian Eisele (University of Manchester) as part of Greek Algebra & Number Th
eory Seminar\n\n\nAbstract\nI will start with an introduction to derived c
ategories and derived equivalences of finite-dimensional algebras\, and th
e notion of silting complexes. I will then talk about results on two large
classes of finite-dimensional algebras\, namely Brauer graph algebras and
the weighted surface algebras introduced by Erdmann and Skowronski\, whic
h show that these algebras have multiplicity-independent sets of silting c
omplexes. The key ingredient for this is the existence of lifts of these a
lgebras to orders over formal power series rings\, which are remarkably si
milar to orders over p-adic rings encountered in the modular representatio
n theory of finite groups.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Céline Maistret (University of Bristol)
DTSTART:20220124T140000Z
DTEND:20220124T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/2
DESCRIPTION:Title: Parity of ranks of abelian surfaces\nby Céline Maistret (Universi
ty of Bristol) as part of Greek Algebra & Number Theory Seminar\n\n\nAbstr
act\nLet $K$ be a number field and $A/K$ an abelian surface. By the Mordel
l-Weil theorem\, the group of $K$-rational points on $A$ is finitely gener
ated and as for elliptic curves\, its rank is predicted by the Birch and S
winnerton-Dyer conjecture. A basic consequence of this conjecture is the p
arity conjecture: the sign of the functional equation of the L-series dete
rmines the parity of the rank of $A/K$. \n\nAssuming finiteness of the Sha
farevich-Tate group\, we prove the parity conjecture for principally polar
ized abelian surfaces under suitable local constraints. Using a similar ap
proach we show that for two elliptic curves $E_1$ and $E_2$ over $K$ with
isomorphic $2$-torsion\, the parity conjecture is true for $E_1$ if and o
nly if it is true for $E_2$. In both cases\, we prove analogous unconditio
nal results for Selmer groups.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ioannis Emmanouil (National and Kapodistrian University of Athens)
DTSTART:20220207T140000Z
DTEND:20220207T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/3
DESCRIPTION:Title: Homological and homotopical properties of unbounded complexes\nby
Ioannis Emmanouil (National and Kapodistrian University of Athens) as part
of Greek Algebra & Number Theory Seminar\n\n\nAbstract\nBousfield localiz
ing pairs in the homotopy category of a ring are non-linear analogues of c
otorsion pairs in the module category. We shall present several examples o
f Bousfield localizing pairs that are related to acyclicity\, flatness and
purity.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Angelos Koutsianas (Aristotle University of Thessaloniki)
DTSTART:20220221T140000Z
DTEND:20220221T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/4
DESCRIPTION:Title: Solving generalized Fermat equations with Frey hyperelliptic curves\nby Angelos Koutsianas (Aristotle University of Thessaloniki) as part of
Greek Algebra & Number Theory Seminar\n\n\nAbstract\nIn this talk\, I wil
l talk about Darmon's program and the resolution of the generalized Ferma
t equation of signature $(p\,p\,5)$ using Frey hyperelliptic curves. This
is joint work with Imin Chen (Simon Fraser University).\n
LOCATION:https://stable.researchseminars.org/talk/GANT/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nikolaos Tziolas (University of Cyprus)
DTSTART:20220314T140000Z
DTEND:20220314T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/5
DESCRIPTION:Title: The role of automorphisms in the classification of surfaces of general
type in characteristic $p>0$.\nby Nikolaos Tziolas (University of Cyp
rus) as part of Greek Algebra & Number Theory Seminar\n\n\nAbstract\nThe c
lassification of varieties of general type is one of the fundamental probl
ems of algebraic geometry. In characteristic zero it is known that varieti
es of general type with fixed volume have a coarse moduli space of finite
type over the base field and the corresponding moduli stack is Deligne-Mum
ford. In positive characteristic the first property is at the moment unkno
wn if it holds in dimensions at least $3$ and the second fails in general
in dimension at least $2$.\n\nIn this talk I will explain how the failure
of the second property is related to the existence of varieties of genera
l type with non reduced automorphism scheme. I will present explicit examp
les of such surfaces and present results regarding their geometry and the
structure of their automorphism scheme.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nicole Raulf (University of Lille)
DTSTART:20220321T140000Z
DTEND:20220321T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/6
DESCRIPTION:Title: Asymptotics of class numbers\nby Nicole Raulf (University of Lille
) as part of Greek Algebra & Number Theory Seminar\n\n\nAbstract\nIn this
talk we present results on the asymptotic behaviour of class numbers in th
e situation that the class numbers are ordered by the size of the regulato
r. We also will discuss the methods that can be used to obtain these resul
ts.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vasiliki Petrotou (University of Ioannina)
DTSTART:20220404T130000Z
DTEND:20220404T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/7
DESCRIPTION:Title: Tom & Jerry Unprojection triples\nby Vasiliki Petrotou (University
of Ioannina) as part of Greek Algebra & Number Theory Seminar\n\n\nAbstra
ct\nUnprojection is a theory in Commutative Algebra due to Miles \nReid wh
ich constructs and analyses more complicated rings from simpler \nones.\n\
nThe talk will be about a new format of unprojection which we call Tom \n&
Jerry triples. The motivation is to construct codimension $6$ Gorenstein\
nrings starting from codimension $3$. As an application we will construct
\ntwo families of codimension $6$ Fano $3$-folds in weighted projective sp
ace.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marc Masdeu (Universitat Autònoma de Barcelona)
DTSTART:20220418T130000Z
DTEND:20220418T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/8
DESCRIPTION:Title: Numerical experiments with plectic Darmon points\nby Marc Masdeu (
Universitat Autònoma de Barcelona) as part of Greek Algebra & Number Theo
ry Seminar\n\n\nAbstract\nLet $E/F$ be an elliptic curve defined over a nu
mber field $F$\, and let $K/F$ be a quadratic extension. If the analytic r
ank of $E(K)$ is one\, one can often use Heegner points (or the more gener
al Darmon points) to produce (at least conjecturally) a nontorsion generat
or of $E(K)$. If the analytic rank of $E(K)$ is larger than one\, the prob
lem of constructing algebraic points is still very open. In recent work\,
Michele Fornea and Lennart Gehrmann have introduced certain $p$-adic quant
ities that may be conjecturally related to the existence of these points.
In this talk I will explain their construction\, and illustrate with some
numerical experiments some support for their conjecture. This is joint wor
k with Michele Fornea and Xevi Guitart.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sofia Lambropoulou (National Technical University of Athens)
DTSTART:20220502T130000Z
DTEND:20220502T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/9
DESCRIPTION:Title: Braidings\, braid equivalences and Jones-type invariants\nby Sofia
Lambropoulou (National Technical University of Athens) as part of Greek A
lgebra & Number Theory Seminar\n\n\nAbstract\nWe will present algorithms f
or turning knots and links into braids in various diagrammatic settings. T
hen we will explain the construction of Jones-type knot and link invariant
s via Markov traces onappropriate quotient algebras of braid groups\n
LOCATION:https://stable.researchseminars.org/talk/GANT/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Morten Risager (University of Copenhagen)
DTSTART:20220516T130000Z
DTEND:20220516T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/10
DESCRIPTION:Title: Distributions of twists of multiple L-series of modular forms.\nb
y Morten Risager (University of Copenhagen) as part of Greek Algebra & Num
ber Theory Seminar\n\n\nAbstract\nStarting with a historical introduction
involving Menogoli\, Goldbach\, Euler and Zagier we introduce certain addi
tive twists of multiple L-series. These turn out to be expressible through
Manin’s iterated integrals. We then go on to describe our recent work o
n the distribution of the central values of these additive twists.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Robin Frot (Alfréd Rényi Institute of Mathematics)
DTSTART:20220606T130000Z
DTEND:20220606T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/11
DESCRIPTION:Title: Explicit bounds for prime gaps and graphic sequence\nby Robin Fro
t (Alfréd Rényi Institute of Mathematics) as part of Greek Algebra & Num
ber Theory Seminar\n\n\nAbstract\nA prime gap graph is defined to be a gra
ph on $n$ vertices with respective degrees $1$ and the $n-1$ first prime g
aps. In a recent paper of P. Erdős\, G. Harcos\, S. Kharel\, P. Maga\, T
. Mezei\, Z. Toroczkai\, they proved that under RH\, prime gap graphs exis
t for every $n$. Also they exist unconditionally for $n$ large enough. Mor
eover\, it is possible to give an iterative construction of these graphs.
\n\nThe ideas in this result lie between elementary number theory\, graph
theory and combinatorics. In this talk\, I will explain how to obtain this
result in its unconditional form\, while trying to find explicitly how la
rge $n$ should be to get a graphic sequence.\n\nThis talk is based on the
aforementioned paper\, and a joint work with Keshav Aggarwal.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tiago Cruz (Universität Stuttgart)
DTSTART:20220523T130000Z
DTEND:20220523T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/12
DESCRIPTION:Title: Ringel self-duality via relative dominant dimension\nby Tiago Cru
z (Universität Stuttgart) as part of Greek Algebra & Number Theory Semina
r\n\n\nAbstract\nQuasi-hereditary algebras provide an abstract framework f
or the homological structure of Schur algebras and the BGG category $O$ of
a semi-simple Lie algebra and they always appear in pairs via Ringel dual
ity.\n\nIn this talk\, we discuss a generalisation of dominant dimension u
sing relative homological algebra. This homological invariant is compatibl
e with the tools from integral representation theory and it increases our
understanding of classical dominant dimension.\n\nIn particular\, this hom
ological invariant provides tools to deduce that quasi-hereditary covers f
ormed by quasi-hereditary algebras with a simple preserving duality with l
arge enough dominant dimension also appear in pairs. As an application\, w
e give a new proof of Ringel self-duality of the blocks of the BGG categor
y $O$ of a complex semi-simple Lie algebra.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stevan Gajovic (Max Planck Institute for Mathematics\, Bonn)
DTSTART:20221003T130000Z
DTEND:20221003T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/13
DESCRIPTION:Title: Quadratic Chabauty for integral points and p-adic heights on even deg
ree hyperelliptic curves\nby Stevan Gajovic (Max Planck Institute for
Mathematics\, Bonn) as part of Greek Algebra & Number Theory Seminar\n\n\n
Abstract\nThe method of Chabauty and Coleman is a powerful method to deter
mine rational points on curves whose Jacobian has the Mordell-Weil rank ov
er $\\mathbb{Q}$ (denoted by $r$) less than its genus (denoted by $g$). In
this talk\, we show how to construct a locally analytic function\, using
$p$-adic (Coleman-Gross) heights\, that we use to compute integral points
on certain even degree hyperelliptic curves when $r=g$. This is joint work
with Steffen Müller.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Maria Chlouveraki (National and Kapodistrian University of Athens)
DTSTART:20221017T130000Z
DTEND:20221017T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/14
DESCRIPTION:Title: The defect of blocks in Hecke algebras\nby Maria Chlouveraki (Nat
ional and Kapodistrian University of Athens) as part of Greek Algebra & Nu
mber Theory Seminar\n\n\nAbstract\nWhen an algebra is not semisimple\, a g
ood way to understand its representation theory is through the study of it
s blocks. To each simple module in a block we can attach a numerical datum
\, which measures the complexity of the block: the defect. This is true fo
r the symmetric group algebra\, as well as its generalisations\, the Iwaho
ri-Hecke algebra of type A and the Ariki-Koike algebra. In a joint work w
ith Nicolas Jacon we have proved\, using algebraic combinatorics\, that th
e defect is a block invariant for Ariki-Koike algebras\, thus proving a co
njecture formulated by Geck 30 years ago. In this talk we will present our
proof\, as well as our data indicating that this fact is true for all Hec
ke algebras associated with complex reflection groups.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ioannis Tsokanos (The University of Manchester)
DTSTART:20221031T140000Z
DTEND:20221031T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/15
DESCRIPTION:Title: Density of oscillating sequences in the real line\nby Ioannis Tso
kanos (The University of Manchester) as part of Greek Algebra & Number The
ory Seminar\n\n\nAbstract\nIn this talk\, we study the density properties
in the real line of oscillating sequences of the form $( g(k) \\cdot F(ka)
)_{k \\in \\mathbb{N}}$\, where $g$ is a positive increasing function an
d $F$ a real continuous $1$-periodic function. This extends work by Berend
\, Boshernitzan and Kolesnik who established differential properties on th
e function $F$ ensuring that the oscillating sequence is dense modulo $1$.
More precisely\, when F has finitely many roots in $[0\,1)$\, we provide
necessary and sufficient conditions for the oscillating sequence under con
sideration to be dense in $\\mathbb{R}$. All the related results are state
d in terms of the Diophantine properties of $a$\, with the help of the the
ory of continued fractions.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eleni Tzanaki (University of Crete)
DTSTART:20221128T140000Z
DTEND:20221128T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/16
DESCRIPTION:Title: Symmetric decompositions\, triangulations and real-rootedness\nby
Eleni Tzanaki (University of Crete) as part of Greek Algebra & Number The
ory Seminar\n\n\nAbstract\nA triangulation of a simplicial complex $Δ$ is
said to be uniform if the $f$-vector of its restriction to a face of $Δ$
depends only on the dimension of that face. The notion of uniform triangu
lation was introduced by Christos Athanasiadis in order to conveniently un
ify many well known types of triangulations such as barycentric\, $r$-colo
red barycentric\, $r$-fold edgewise etc. These triangulations have the com
mon feature that\, for certain "nice" classes of simplicial complexes $Δ$
\, the $h$-polynomial of the triangulation $Δ^′$ of $Δ$\, is real root
ed with nonnegative coefficients. Athanasiadis proved that\, uniform trian
gulations having the so called stong interlacing property\, have real root
ed $h$-polynomials with nonnegative coefficients.\n\nWe continue this line
of research and we study under which conditions the $h$-polynomial of a u
niform triangulation $Δ^′$ of $Δ$ has a nonnegative real rooted symmet
ric decomposition. We also provide conditions under which this decompositi
on is also interlacing. Applications yield new classes of polynomials in g
eometric combinatorics which afford nonnegative\, real-rooted symmetric de
compositions. Some interesting questions in $h$-vector theory arise from t
his work.\n\nThis is joint work with Christos Athanasiadis.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Konstantinos Tsouvalas (IHÉS)
DTSTART:20221114T140000Z
DTEND:20221114T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/17
DESCRIPTION:Title: Anosov groups that are indiscrete in rank one\nby Konstantinos Ts
ouvalas (IHÉS) as part of Greek Algebra & Number Theory Seminar\n\n\nAbst
ract\nHyperbolic groups is a rich and well-studied class of finitely prese
nted groups introduced by Gromov in the 80's. It is an open question on wh
ether there exist examples of linear hyperbolic groups which do not admit
discrete faithful representation into any real semisimple Lie group. In th
is talk\, we are going to provide linear examples of hyperbolic groups whi
ch\, on the one hand admit Anosov representations into higher rank Lie gro
ups\, but fail to admit discrete faithful representation into any product
of (finitely many) rank one Lie groups. This is joint work with Sami Douba
.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stelios Sachpazis (Université de Montréal)
DTSTART:20221212T140000Z
DTEND:20221212T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/18
DESCRIPTION:Title: A different proof of Linnik's estimate for primes in arithmetic progr
essions\nby Stelios Sachpazis (Université de Montréal) as part of Gr
eek Algebra & Number Theory Seminar\n\n\nAbstract\nLet $a$ and $q$ be two
coprime positive integers. In 1944\, Linnik\nproved his celebrated theorem
concerning the size of the smallest prime\n$p(q\,a)$ in the arithmetic pr
ogression $a(\\mod q)$. In his attempt to prove\nhis result\, Linnik estab
lished an estimate for the sums of the von Mangoldt\nfunction $\\Lambda$ o
n arithmetic progressions. His work on $p(q\,a)$ was later\nsimplified\, b
ut the simplified proofs relied in one form or another on the\nsame advanc
ed tools that Linnik originally used. The last two decades\, some\nmore el
ementary approaches for Linnik's theorem have appeared. Nonetheless\,\nnon
e of them furnishes an estimate of the same quantitative strength as the\n
one that Linnik obtained for $\\Lambda$. In this talk\, we will see how on
e can seal\nthis gap and recover Linnik’s estimate by largely elementary
means. The\nideas that I will describe build on methods from the treatmen
t of\nKoukoulopoulos on multiplicative functions with small partial sums a
nd his\npretentious proof for the prime number theorem in arithmetic progr
essions.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anastasia Hadjievangelou (University of Bath)
DTSTART:20230130T140000Z
DTEND:20230130T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/19
DESCRIPTION:Title: Left 3-Engel Elements in Locally Finite p-groups\nby Anastasia Ha
djievangelou (University of Bath) as part of Greek Algebra & Number Theory
Seminar\n\n\nAbstract\nEngel Theory is of significant interest in group t
heory as there\nis an unmistakable correlation between Engel and Burnside
problems. In\nthis talk we first introduce Engel elements and Engel groups
and in\nparticular we expand our knowledge on locally finite Engel groups
. It is\nimportant to know that M. Newell proved that if $x$ is a right $3
$-Engel\nelement in a group $G$ then $x$ lies in $HP(G)$ (Hirsch-Plotkin r
adical) and in\nfact he proved the stronger result that the normal closure
of $x$ is\nnilpotent of class at most $3$. The natural question arises wh
ether the\nanalogous result holds for left $3$-Engel elements. We will giv
e various\nexamples of locally finite p-groups $G$ containing a left $3$-E
ngel element $x$\nwhose normal closure is not nilpotent. Lastly\, we will
discuss the open\nproblem of whether or not a left $3$-Engel element alway
s lies in the $HP(G)$.\n(This is joint work with Gunnar Traustason and Mar
ialaura Noce)\n
LOCATION:https://stable.researchseminars.org/talk/GANT/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christina Vasilakopoulou (National Technical University of Athens)
DTSTART:20230116T140000Z
DTEND:20230116T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/20
DESCRIPTION:Title: Dual algebraic structures and enrichment\nby Christina Vasilakopo
ulou (National Technical University of Athens) as part of Greek Algebra &
Number Theory Seminar\n\n\nAbstract\nIn this talk\, we will provide an ove
rview of the sometimes called “Sweedler theory” for algebras and modul
es. This begins by establishing an enrichment of the category of algebras
in the category of coalgebras\, as well as an enrichment of a global categ
ory of modules in a global category of comodules\, giving rise to a struct
ure described as an enriched fibration. Moreover\, by investigating a many
-object generalization involving categories and modules\, we will discuss
further directions and applications of this framework to operadic structur
es.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Maria Loukaki (University of Crete)
DTSTART:20230220T140000Z
DTEND:20230220T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/21
DESCRIPTION:Title: Congruences in finite $p$-groups\nby Maria Loukaki (University of
Crete) as part of Greek Algebra & Number Theory Seminar\n\n\nAbstract\nLe
t $G$ be a finite $p$-group. How many abelian subgroups of a\ngiven order
does $G$ have $\\pmod p$? Elementary abelian? What about normal\nabelian o
r normal elementary abelian? This type of questions we will try to\nanswer
\, for any subgroup-closed class $\\mathfrak{X}$ of finite groups\, in\nth
is joint work with S. Aivazidis. Relations to known results\, a sharpened\
nversion of a celebrated theorem of Burnside and some open questions are\n
also presented.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Myrto Mavraki (Harvard University)
DTSTART:20230327T130000Z
DTEND:20230327T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/22
DESCRIPTION:Title: Dynamics\, number theory and unlikely intersections\nby Myrto Mav
raki (Harvard University) as part of Greek Algebra & Number Theory Seminar
\n\n\nAbstract\nFruitful interactions between arithmetic geometry and dyna
mical systems have emerged in recent years. In this talk I will illustrate
how insights from complex dynamics can be employed to study problems from
arithmetic geometry. And conversely how arithmetic geometry can be used i
n the study of dynamical systems. The motivating questions are inspired by
a recurring phenomenon in arithmetic geometry known as `unlikely intersec
tions' and conjectures of Pink and Zilber therein. More specifically\, I w
ill discuss work toward understanding the distribution of preperiodic poin
ts in subvarieties of families of rational maps.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chris Birkbeck (University of East Anglia)
DTSTART:20230213T140000Z
DTEND:20230213T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/23
DESCRIPTION:Title: Overconvergent Hilbert modular forms via perfectoid methods\nby C
hris Birkbeck (University of East Anglia) as part of Greek Algebra & Numbe
r Theory Seminar\n\n\nAbstract\nFollowing a construction of Chojecki-Hanse
n-Johansson\, we show how to use Scholze's infinite level modular varietie
s and the Hodge-Tate period map to define overconvergent elliptic and Hilb
ert modular forms in a way analogous to the standard construction of modul
ar forms. As an application we show that this is one way of constructing o
verconvergent Eichler-Shimura maps in these settings. This is joint work w
ith Ben Heuer and Chris Williams.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Giorgos Kapetanakis (University of Thessaly)
DTSTART:20230410T130000Z
DTEND:20230410T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/25
DESCRIPTION:Title: Towards the Primitive Completely Normal Basis Theorem\nby Giorgos
Kapetanakis (University of Thessaly) as part of Greek Algebra & Number Th
eory Seminar\n\n\nAbstract\nLet GF(q) be the finite field of cardinality q
and GF(q^n) its extension of degree n. A generator of the multiplicative
group GF(q^n)^* is called primitive and some x in GF(q^n) whose GF(q)-conj
ugates span a GF(q)-basis is called normal over GF(q). In 1996\, Morgan an
d Mullen conjectured that for every q and n\, there exists some primitive
element of GF(q^n) that is normal over GF(q^d) for every d|n.\nIn this tal
k\, we will describe how this conjecture was established when q>n and we w
ill discuss possible improvements. This is joint work with Theodoulos Gare
falakis.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ekin Özman (Boğaziçi University)
DTSTART:20230424T130000Z
DTEND:20230424T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/26
DESCRIPTION:Title: Modular Curves and Asymptotic Solutions to Fermat-type Equations\
nby Ekin Özman (Boğaziçi University) as part of Greek Algebra & Number
Theory Seminar\n\n\nAbstract\nUnderstanding solutions of Diophantine equat
ions over a number field is one of the main problems of number theory. By
the help of the modular techniques used in the proof of Fermat’s last th
eorem by Wiles and its generalizations\, it is possible to solve other Dio
phantine equations too. Understanding quadratic points on the classical mo
dular curve also plays a role in this approach. It is also possible to stu
dy the solutions of Fermat type equations over number fields asymptoticall
y. In this talk\, I will mention some recent results about these notions f
or the classical Fermat equation as well as some other Diophantine equatio
ns.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yiannis Vlassopoulos (Athena RC)
DTSTART:20230313T140000Z
DTEND:20230313T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/27
DESCRIPTION:Title: Language modelling with enriched categories\, the Yoneda embedding an
d the Isbell completion\nby Yiannis Vlassopoulos (Athena RC) as part o
f Greek Algebra & Number Theory Seminar\n\n\nAbstract\nNeural networks (li
ke ChatGPT) trained to probabilistically predict the next word to a text\,
have recently achieved human like capabilities in language understanding
and use.\n\nWhat is though the underlying mathematical structure that thes
e models learn and how is semantic information encoded in the statistics o
f word co-occurances?\n\nWe will introduce a category L whose objects are
texts in the language and a morphism from text x to text y is the probabil
ity of extension from x to y\, in order to propose a partial answer to the
se questions. The category is enriched over the monoidal closed category w
hose set of objects is [0\, 1] and monoidal structure is multiplication. T
he Yoneda embedding of L into its category of presheaves naturally encodes
co-occurance information. Applying −log to morphisms we obtain an equiv
alent category which is also a Lawvere metric space and a tropical linear
space. We will then explain the Isbell completion which relates completion
by op co-presheaves (probabilites of extending a text) to completion by p
resheaves (probabilities of extending to a text). This is based on joint w
ork with T.D. Bradley\, J. Terilla and S. Gaubert.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Theo Douvropoulos (University of Massachusetts at Amherst)
DTSTART:20230508T130000Z
DTEND:20230508T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/28
DESCRIPTION:Title: Recursions and Proofs in Coxeter-Catalan combinatorics\nby Theo D
ouvropoulos (University of Massachusetts at Amherst) as part of Greek Alge
bra & Number Theory Seminar\n\n\nAbstract\nIn a significant --yet absolute
ly understandable-- deviation from traditions of logic\, secularism\, and
platonic dialectic\, combinatorialists the world around have celebrated Ca
talan objects with a reverence better suited to mystical\, preternatural e
ndeavors. Various sects have been formed through the years by mathematicia
ns who study particular aspects of the Catalan doctrine\, including the Co
xeter-Catalan sect of which the speaker might be a member.\n\nOne of the c
entral objects in Coxeter-Catalan combinatorics is the noncrossing partiti
on lattice $NC(W)$ associated to a finite Coxeter group $W$ and its siblin
g object\, the cluster complex $Y(W)$. These two objects encode much of th
e geometric group theory\, combinatorics\, and representation theory of $W
$\, and they have fascinating stuctural and enumerative properties\; in pa
rticular\, the zeta polynomials of certain intervals in $NC(W)$ and the (a
lmost) colored $f$-vectors of $Y(W)$ all have product formulas given in te
rms of invariants of $W$ (generalizing formulas of Kreweras and Loday for
the symmetric group case). A central open problem in the area since at lea
st the early 2000's has been to give case-free proofs of these product for
mulas\, i.e. proofs that do not depend on the classification of finite Cox
eter groups. In this talk\, I will present the first such proof\, in colla
boration with Matthieu Josuat-Verges\, solving the more general Fuss versi
on of the problem\; in our approach\, we develop a collection of recursion
s that are shown to be satisfied by both the combinatorial objects and the
product formulas.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vasileios Metaftsis (University of the Aegean)
DTSTART:20230529T130000Z
DTEND:20230529T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/29
DESCRIPTION:Title: Some steps towards understanding the McCool group\nby Vasileios M
etaftsis (University of the Aegean) as part of Greek Algebra & Number Theo
ry Seminar\n\n\nAbstract\nWe give a brief introduction to the group of aut
omorphisms of the free group and we give some results concerning the McCoo
l subgroup and some subgroups of it.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:George Dalezios (Aristotle University of Thessaloniki)
DTSTART:20231113T120000Z
DTEND:20231113T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/30
DESCRIPTION:Title: Stable and singular equivalences of finite dimensional algebras I
\nby George Dalezios (Aristotle University of Thessaloniki) as part of Gre
ek Algebra & Number Theory Seminar\n\n\nAbstract\nThe plan is to give two
talks on homological methods in the representation theory of finite dimens
ional associative algebras\, culminating in recent new results on stable a
nd singular equivalences. The first talk will be introductory\, offering a
crash course on concepts such as quiver representations and Morita equiva
lences (classical and derived). In the second talk\, we will go beyond the
class of derived equivalences and discuss singularity categories and sing
ular equivalences\, in relation to Gorenstein rings and Cohen-Macaulay mod
ules. Effort will be put in making things comprehensive to a broad algebra
ic audience.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:George Dalezios (Aristotle University of Thessaloniki)
DTSTART:20231120T120000Z
DTEND:20231120T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/31
DESCRIPTION:Title: Stable and singular equivalences of finite dimensional algebras II\nby George Dalezios (Aristotle University of Thessaloniki) as part of Gr
eek Algebra & Number Theory Seminar\n\n\nAbstract\nThe plan is to give two
talks on homological methods in the representation theory of finite dimen
sional associative algebras\, culminating in recent new results on stable
and singular equivalences. The first talk will be introductory\, offering
a crash course on concepts such as quiver representations and Morita equiv
alences (classical and derived). In the second talk\, we will go beyond th
e class of derived equivalences and discuss singularity categories and sin
gular equivalences\, in relation to Gorenstein rings and Cohen-Macaulay mo
dules. Effort will be put in making things comprehensive to a broad algebr
aic audience.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kostas Psaromiligkos (Université Clermont Auvergne)
DTSTART:20231204T140000Z
DTEND:20231204T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/32
DESCRIPTION:Title: Deformation theory of the Lafforgue variety - part 1\nby Kostas P
saromiligkos (Université Clermont Auvergne) as part of Greek Algebra & Nu
mber Theory Seminar\n\n\nAbstract\nIn this series of talks we will constru
ct the Lafforgue variety\, an affine scheme equipped with an open dense su
bscheme parametrizing the simple modules of a non-commutative algebra that
is a finite module over a finitely generated center. Our main application
s and source of examples will be in the theory of Hecke algebras. We will
also study how the Lafforgue variety varies under deformation of algebras\
, and in particular we prove in the case the center is regular a conjectur
e stated by Aubert\, Baum and Plymen in 2007 on the reducibility loci of a
ffine Hecke algebras.\n\nIn the first talk\, we will introduce Hecke algeb
ras and the type of questions we will consider\, as well as relevant algeb
raic geometric notions for the second talk. In the second talk\, we will c
onstruct the Lafforgue variety and study its deformation theory (the latte
r is work in progress).\n
LOCATION:https://stable.researchseminars.org/talk/GANT/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kostas Psaromiligkos (Université Clermont Auvergne)
DTSTART:20231211T140000Z
DTEND:20231211T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/33
DESCRIPTION:Title: Deformation theory of the Lafforgue variety - part 2\nby Kostas P
saromiligkos (Université Clermont Auvergne) as part of Greek Algebra & Nu
mber Theory Seminar\n\n\nAbstract\nIn this series of talks we will constru
ct the Lafforgue variety\, an affine scheme equipped with an open dense su
bscheme parametrizing the simple modules of a non-commutative algebra that
is a finite module over a finitely generated center. Our main application
s and source of examples will be in the theory of Hecke algebras. We will
also study how the Lafforgue variety varies under deformation of algebras\
, and in particular we prove in the case the center is regular a conjectur
e stated by Aubert\, Baum and Plymen in 2007 on the reducibility loci of a
ffine Hecke algebras.\n\nIn the first talk\, we will introduce Hecke algeb
ras and the type of questions we will consider\, as well as relevant algeb
raic geometric notions for the second talk. In the second talk\, we will c
onstruct the Lafforgue variety and study its deformation theory (the latte
r is work in progress).\n
LOCATION:https://stable.researchseminars.org/talk/GANT/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zafeirakis Zafeirakopoulos (Gebze Technical University)
DTSTART:20240122T140000Z
DTEND:20240122T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/34
DESCRIPTION:Title: Linear Diophantine Systems\, Integer Partitions\, Polyhedra and Appl
ications - Part 1\nby Zafeirakis Zafeirakopoulos (Gebze Technical Univ
ersity) as part of Greek Algebra & Number Theory Seminar\n\nAbstract: TBA\
n
LOCATION:https://stable.researchseminars.org/talk/GANT/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zafeirakis Zafeirakopoulos (Gebze Technical University)
DTSTART:20240129T140000Z
DTEND:20240129T150000Z
DTSTAMP:20260404T111212Z
UID:GANT/35
DESCRIPTION:Title: Linear Diophantine Systems\, Integer Partitions\, Polyhedra and Appl
ications - Part 2\nby Zafeirakis Zafeirakopoulos (Gebze Technical Univ
ersity) as part of Greek Algebra & Number Theory Seminar\n\nAbstract: TBA\
n
LOCATION:https://stable.researchseminars.org/talk/GANT/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Manolis Tsakiris (Chinese Academy of Sciences)
DTSTART:20240311T120000Z
DTEND:20240311T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/36
DESCRIPTION:Title: Castelnuovo-Mumford regularity of subspace arrangements - Part 1\
nby Manolis Tsakiris (Chinese Academy of Sciences) as part of Greek Algebr
a & Number Theory Seminar\n\n\nAbstract\nIn the first talk of this seminar
\, after reviewing the notion of Castelnuovo-Mumford regularity of a finit
ely generated graded module over a polynomial ring with coefficients in a
field\, some history and known results will be discussed regarding the reg
ularity of ideals associated to subspace arrangements and the connections
with their Hilbert functions. The subject of second talk will be recent re
sults obtained together with Aldo Conca\, which improve the bound of Derks
en & Sidman (2002) for arrangements of generic linear spaces in projective
space of codimension at least 2.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Georgios Raptis (Universität Regensburg)
DTSTART:20211022T130000Z
DTEND:20211022T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/37
DESCRIPTION:Title: Higher homotopy categories and their uses\nby Georgios Raptis (Un
iversität Regensburg) as part of Greek Algebra & Number Theory Seminar\n\
nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aristides Kontogeorgis (National and Kapodistrian University of At
hens)
DTSTART:20211101T120000Z
DTEND:20211101T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/38
DESCRIPTION:Title: Group actions on Families of Curves\nby Aristides Kontogeorgis (N
ational and Kapodistrian University of Athens) as part of Greek Algebra &
Number Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kostas Karagiannis (University of Manchester)
DTSTART:20231023T110000Z
DTEND:20231023T120000Z
DTSTAMP:20260404T111212Z
UID:GANT/43
DESCRIPTION:Title: Polynomial invariants of finite group schemes - Part 2\nby Kostas
Karagiannis (University of Manchester) as part of Greek Algebra & Number
Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Manolis Tsakiris (Chinese Academy of Sciences)
DTSTART:20240321T120000Z
DTEND:20240321T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/45
DESCRIPTION:Title: Castelnuovo-Mumford regularity of subspace arrangements - Part 2\
nby Manolis Tsakiris (Chinese Academy of Sciences) as part of Greek Algebr
a & Number Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kostas Karagiannis (University of Manchester)
DTSTART:20231030T120000Z
DTEND:20231030T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/51
DESCRIPTION:Title: Polynomial invariants of finite group schemes - Part 3\nby Kostas
Karagiannis (University of Manchester) as part of Greek Algebra & Number
Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Florent Jouve (Institut de Mathématiques de Bordeaux)
DTSTART:20211115T120000Z
DTEND:20211115T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/53
DESCRIPTION:Title: Inequities in the distribution of Frobenius automorphisms in extensio
ns of number fields\nby Florent Jouve (Institut de Mathématiques de B
ordeaux) as part of Greek Algebra & Number Theory Seminar\n\nAbstract: TBA
\n
LOCATION:https://stable.researchseminars.org/talk/GANT/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Damiano Testa (University of Warwick)
DTSTART:20211129T120000Z
DTEND:20211129T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/54
DESCRIPTION:Title: Lines of polynomials with Galois group $A_{2n}$\nby Damiano Testa
(University of Warwick) as part of Greek Algebra & Number Theory Seminar\
n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tasos Moulinos (Institut de Mathématiques de Toulouse)
DTSTART:20211213T120000Z
DTEND:20211213T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/55
DESCRIPTION:Title: Derived algebraic geometry and the filtered circle\nby Tasos Moul
inos (Institut de Mathématiques de Toulouse) as part of Greek Algebra & N
umber Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kostas Karagiannis (University of Manchester)
DTSTART:20231016T110000Z
DTEND:20231016T120000Z
DTSTAMP:20260404T111212Z
UID:GANT/56
DESCRIPTION:Title: Polynomial invariants of finite group schemes - Part 1\nby Kostas
Karagiannis (University of Manchester) as part of Greek Algebra & Number
Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Polyxeni Spilioti (University of Göttingen)
DTSTART:20240408T110000Z
DTEND:20240408T120000Z
DTSTAMP:20260404T111212Z
UID:GANT/61
DESCRIPTION:Title: Trace formulas and dynamical zeta functions for non-unitary twists I<
/a>\nby Polyxeni Spilioti (University of Göttingen) as part of Greek Alge
bra & Number Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Polyxeni Spilioti (University of Göttingen)
DTSTART:20240422T110000Z
DTEND:20240422T120000Z
DTSTAMP:20260404T111212Z
UID:GANT/62
DESCRIPTION:Title: Trace formulas and dynamical zeta functions for non-unitary twists II
\nby Polyxeni Spilioti (University of Göttingen) as part of Greek Alg
ebra & Number Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/62/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Athanasios Sourmelidis (Graz University of Technology)
DTSTART:20240520T110000Z
DTEND:20240520T120000Z
DTSTAMP:20260404T111212Z
UID:GANT/63
DESCRIPTION:Title: On the interface of universal zeta-functions and frequently hypercycl
ic vectors of translation operators\nby Athanasios Sourmelidis (Graz U
niversity of Technology) as part of Greek Algebra & Number Theory Seminar\
n\n\nAbstract\nIf $\\Omega \\subseteq \\mathbb{C}$ is a simply connected d
omain and $H(\\Omega)$ is the Fréchet space of holomorphic functions on $
\\Omega$\, then it is well-known from linear dynamics that there is a dens
e $G_{\\delta}$ set of $H(\\Omega)$ such that for any element $f$ from thi
s set\, the set $\\{f( \\cdot + i\\tau ) : \\tau \\in \\mathbb{R} \\}$ is
dense in $H(\\Omega)$. However\, no information is provided on how these e
lements $f$ look like. Despite that\, in the special case when $\\Omega$ i
s\nthe vertical strip of complex numbers with real part between $1/2$ and
$1$\, Sergei Voronin proved using analytic number theoretical methods that
the Riemann zeta-function $\\zeta$ is universal in the sense that the set
$\\{\\log \\zeta( \\cdot + i\\tau ) : \\tau \\in \\mathbb{R} \\}$ is dens
e in $H(\\Omega)$. This phenomenon has now been observed for a large class
of “zeta-functions”. In these talks I will discuss about the aforemen
tioned results and draw connections between the theory of translation oper
ators and the theory of universal zeta-functions in the form of applicatio
ns and research questions.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Athanasios Sourmelidis (Graz University of Technology)
DTSTART:20240527T110000Z
DTEND:20240527T120000Z
DTSTAMP:20260404T111212Z
UID:GANT/64
DESCRIPTION:Title: On the interface of universal zeta-functions and frequently hypercycl
ic vectors of translation operators\nby Athanasios Sourmelidis (Graz U
niversity of Technology) as part of Greek Algebra & Number Theory Seminar\
n\n\nAbstract\nIf $\\Omega \\subseteq \\mathbb{C}$ is a simply connected d
omain and $H(\\Omega)$ is the Fréchet space of holomorphic functions on $
\\Omega$\, then it is well-known from linear dynamics that there is a dens
e $G_{\\delta}$ set of $H(\\Omega)$ such that for any element $f$ from thi
s set\, the set $\\{f( \\cdot + i\\tau ) : \\tau \\in \\mathbb{R} \\}$ is
dense in $H(\\Omega)$. However\, no information is provided on how these e
lements $f$ look like. Despite that\, in the special case when $\\Omega$ i
s\nthe vertical strip of complex numbers with real part between $1/2$ and
$1$\, Sergei Voronin proved using analytic number theoretical methods that
the Riemann zeta-function $\\zeta$ is universal in the sense that the set
$\\{\\log \\zeta( \\cdot + i\\tau ) : \\tau \\in \\mathbb{R} \\}$ is dens
e in $H(\\Omega)$. This phenomenon has now been observed for a large class
of “zeta-functions”. In these talks I will discuss about the aforemen
tioned results and draw connections between the theory of translation oper
ators and the theory of universal zeta-functions in the form of applicatio
ns and research questions.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/64/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Georgios Papas (Hebrew University of Jerusalem)
DTSTART:20241107T130000Z
DTEND:20241107T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/65
DESCRIPTION:Title: Some cases of the Zilber-Pink conjecture in $Y(1)^n$.\nby Georgio
s Papas (Hebrew University of Jerusalem) as part of Greek Algebra & Number
Theory Seminar\n\n\nAbstract\nThe Zilber-Pink conjecture is a far reachin
g and widely open conjecture in the area of "unlikely intersections" gener
alizing many previous results in the area\, such as the recently establish
ed André-Oort conjecture. In the case of curves in $Y(1)^n$\, thanks to w
ork of Habegger and Pila\, the conjecture has been reduced to the purely a
rithmetic problem of establishing lower bounds for certain Galois orbits.
I will discuss how a method first introduced by Y. André that produces he
ight bounds helps us establish the needed bounds for Galois orbits\, and t
hus cases of Zilber-Pink\, for certain curves in $Y(1)^n$.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/65/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anargyros Katsampekis (University of Ioannina)
DTSTART:20241121T130000Z
DTEND:20241121T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/66
DESCRIPTION:Title: Generators of toric ideals associated with semigroups generated by fo
ur positive integers.\nby Anargyros Katsampekis (University of Ioannin
a) as part of Greek Algebra & Number Theory Seminar\n\n\nAbstract\nIn this
talk\, we will provide a minimal binomial generating set for the toric id
eal of a semigroup generated by four positive integers. Our approach relie
s on the detection of those binomials and monomials that have to appear in
every system of binomial generators of the toric ideal.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/66/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Georgios Kotsovolis (Princeton University)
DTSTART:20241205T130000Z
DTEND:20241205T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/67
DESCRIPTION:Title: Bass Note Spectra of Binary Forms\nby Georgios Kotsovolis (Prince
ton University) as part of Greek Algebra & Number Theory Seminar\n\n\nAbst
ract\nFor some homogeneous polynomial $P$ in $k$ variables and some unimod
ular $k$-dimensional lattice $\\Lambda$\, what is the smallest value that
$\\vert P\\vert$ assumes on the non-zero vectors of $\\Lambda$? The set we
obtain by varying $\\Lambda$ in the moduli space of unimodular lattices\,
is referred to as the bass note spectrum of $P$. While this set is fundam
ental in the geometry of numbers\, not many cases are understood. Even in
dimension 2\, the problem has been solved only when $P$ is $\\mathbb{R}$-a
nisotropic or a quadratic form. In this talk\, we will explain Mordell's a
nd Davenport's theorems on the spectra of binary cubic forms and further e
xplain how to resolve this problem for all binary forms of any degree.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/67/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Faidon Andriopoulos
DTSTART:20250109T130000Z
DTEND:20250109T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/68
DESCRIPTION:Title: On the motivic filtration of TR\nby Faidon Andriopoulos as part o
f Greek Algebra & Number Theory Seminar\n\n\nAbstract\nEver since the work
of Grothendieck\, cohomology theories have proved to be indispensable too
ls in the study of algebraic geometry. They fit together under his visiona
ry theory of motives\, which in turn\, is intricately related to the study
of algebraic K-theory and its motivic filtration.\nIn recent years\, grea
t new developments have occurred in the $p$-adic setting\, with the develo
pment of prismatic cohomology and the study of the motivic filtration of t
opological Hochschild homology (THH) and its associated invariants.\nWe pl
an to give a gentle introduction to some of these phenomena\, by highlight
ing the role of the Witt vectors\, working towards an understanding of the
motivic filtration of topological restriction homology (TR).\n
LOCATION:https://stable.researchseminars.org/talk/GANT/68/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ilias Andreou (National and Kapodistrian University of Athens)
DTSTART:20250227T130000Z
DTEND:20250227T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/69
DESCRIPTION:Title: Brauer algebras for complex reflection groups\nby Ilias Andreou (
National and Kapodistrian University of Athens) as part of Greek Algebra &
Number Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/69/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eirini Chavli (University of Stuttagrt)
DTSTART:20250327T130000Z
DTEND:20250327T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/71
DESCRIPTION:Title: Nakayama algebras via combinatorics\nby Eirini Chavli (University
of Stuttagrt) as part of Greek Algebra & Number Theory Seminar\n\n\nAbstr
act\nA Nakayama algebra is a finite-dimensional algebra over a field\, all
whose indecomposable projective and indecomposable injective modules are
uniserial. The aim of this talk is to provide a dictionary between homolog
ical properties of Nakayama algebras and their modules\, and combinatorial
statistics on Dyck paths and 321-avoiding permutations (joint work with R
ené Marczinzik).\n
LOCATION:https://stable.researchseminars.org/talk/GANT/71/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Danai Deligeorgaki (KTH Sweden)
DTSTART:20250410T120000Z
DTEND:20250410T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/72
DESCRIPTION:Title: Colored multiset Eulerian polynomials\nby Danai Deligeorgaki (KTH
Sweden) as part of Greek Algebra & Number Theory Seminar\n\n\nAbstract\nT
he central objects in this talk are the descent polynomials of colored per
mutations on multisets\, referred to as colored multiset Eulerian polynomi
als. These polynomials generalize the colored Eulerian polynomials that ap
pear frequently in algebraic combinatorics and are known to admit desirabl
e distributional properties\, including real-rootedness\, log-concavity\,
unimodality and the alternatingly increasing property. In joint work with
Bin Han and Liam Solus\, symmetric colored multiset Eulerian polynomials a
re identified and used to prove sufficient conditions for a colored multis
et Eulerian polynomial to satisfy the self-interlacing property. This prop
erty implies that the polynomial obtains all of the aforementioned distrib
utional properties as well as others\, including bi-gamma-positivity. To d
erive these results\, multivariate generalizations of a generating functio
n identity due to MacMahon are deduced. The results are applied to a pair
of questions\, both previously studied in several special cases\, that are
seen to admit more general answers when framed in the context of colored
multiset Eulerian polynomials. The first question pertains to s-Eulerian p
olynomials\, and the second to interpretations of gamma-coefficients. We w
ill see some of these results in detail\, depending on the pace of the tal
k\n
LOCATION:https://stable.researchseminars.org/talk/GANT/72/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Asimina Hamakiotes (University of Connecticut)
DTSTART:20240219T130000Z
DTEND:20240219T140000Z
DTSTAMP:20260404T111212Z
UID:GANT/73
DESCRIPTION:Title: Elliptic curves with complex multiplication and abelian division fiel
ds\nby Asimina Hamakiotes (University of Connecticut) as part of Greek
Algebra & Number Theory Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/73/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christos Tatakis (University of Western Macedonia)
DTSTART:20250508T120000Z
DTEND:20250508T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/75
DESCRIPTION:Title: Toric ideals of graphs minimally generated by a Grοbner basis\nb
y Christos Tatakis (University of Western Macedonia) as part of Greek Alge
bra & Number Theory Seminar\n\n\nAbstract\nThe problem of describing famil
ies of ideals minimally generated by either one or all of its Grobner base
s is a central topic in commutative algebra. This work tackles this proble
m in the context of toric ideals of graphs. We call a graph G an MG-graph
if its toric ideal IG is minimally generated by a Grobner basis\, while we
say that G is an UMG-graph if every reduced Grobner basis of IG is a min
imal generating set. We prove that G is an UMG-graph if and only if IG is
a generalized robust ideal\, i.e. ideal whose universal Grobner ̈ basis
and universal Markov basis coincide. We observe that the class of MG-graph
s is not closed under taking subgraphs\, and we prove that it is hereditar
y (i.e.\, closed under taking induced subgraphs). Also\, we describe two f
amilies of bipartite MG-graphs: ring graphs and graphs whose induced cycle
s have the same length. The latter extends a result of Ohsugi and Hibi\, w
hich corresponds to graphs whose induced cycles have all length 4 (joint w
ork with Ignacio Garcia-Marco and Irene Marquez-Corbella).\n
LOCATION:https://stable.researchseminars.org/talk/GANT/75/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andreas Hayash (Aristotle University of Thessaloniki)
DTSTART:20250605T120000Z
DTEND:20250605T130000Z
DTSTAMP:20260404T111212Z
UID:GANT/76
DESCRIPTION:Title: Quantum geometric Langlands and the fundamental local equivalence via
factorization modules\nby Andreas Hayash (Aristotle University of The
ssaloniki) as part of Greek Algebra & Number Theory Seminar\n\n\nAbstract\
nThe goal of the talk is to give an overview of the quantum geometric Lang
lands program\, a categorical manifestation of Langlands duality for reduc
tive groups depending on a parameter. I will discuss recent work in progre
ss (joint with D. Gaitsgory and S. Lysenko) on the fundamental local equiv
alence\, a local result which determines the global theory uniquely.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/76/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dimitra-Dionysia Stergiopoulou (University of Thessaly)
DTSTART:20251030T153000Z
DTEND:20251030T163000Z
DTSTAMP:20260404T111212Z
UID:GANT/77
DESCRIPTION:Title: Gorenstein analogues of a projectivity criterion over group algebras<
/a>\nby Dimitra-Dionysia Stergiopoulou (University of Thessaly) as part of
Greek Algebra & Number Theory Seminar\n\n\nAbstract\nI will talk about a
recent preprint where we formulated and answered Gorenstein projective\, f
lat\, and injective analogues of a classical projectivity question for gro
up rings under some mild additional assumptions. Although the original que
stion\, that was proposed by Jang-Hyun Jo in 2007\, was for integral group
rings\, in our paper\, we dealt with more general commutative base rings.
We made use of the developments that have happened in the field of Gorens
tein homological algebra over group rings in recent years\, and we managed
to improve and generalize several existing results from this area along t
he way. Joint work with Rudradip Biswas.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/77/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Haralampos Geranios (National and Kapodistrian University of Athen
s)
DTSTART:20251127T153000Z
DTEND:20251127T163000Z
DTSTAMP:20260404T111212Z
UID:GANT/78
DESCRIPTION:Title: Relating Representations of the Symmetric Group and the General Linea
r Group\nby Haralampos Geranios (National and Kapodistrian University
of Athens) as part of Greek Algebra & Number Theory Seminar\n\nAbstract: T
BA\n
LOCATION:https://stable.researchseminars.org/talk/GANT/78/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vassilis Dionyssis Moustakas (University of Crete)
DTSTART:20251218T153000Z
DTEND:20251218T163000Z
DTSTAMP:20260404T111212Z
UID:GANT/79
DESCRIPTION:Title: From quasisymmetric functions to zeta functions through shuffle compa
tibility\nby Vassilis Dionyssis Moustakas (University of Crete) as par
t of Greek Algebra & Number Theory Seminar\n\n\nAbstract\nA permutation st
atistic $st$ is called shuffle compatible if\, for any two permutations $\
\pi$ and $\\sigma$ on disjoint sets of symbols\, its distribution over all
shuffles of $\\pi$ and $\\sigma$ depends only on $st(\\pi)$\, $st(\\sigma
)$ and the lengths of $\\pi$ and $\\sigma$. It follows from Stanley’s wo
rk that the descent set constitutes the prototypical example of a shuffle-
compatible permutation statistic. Gessel and Zhuang formalized this notion
by introducing and studying the associated shuffle algebra. In this talk\
, we are going to discuss a colored analogue of shuffle compatibility for
colored permutation statistics and its connection with Poirier’s colored
quasisymmetric functions. Additionally\, we will present an application o
f colored shuffle compatibility in computing Hadamard products of certain
algebraic zeta functions. This is based on joint work with Angela Carneval
e and Tobias Rossmann.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/79/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexios Terezakis (National and Kapodistrian University of Athens
& University of Thessaly)
DTSTART:20260129T153000Z
DTEND:20260129T163000Z
DTSTAMP:20260404T111212Z
UID:GANT/80
DESCRIPTION:Title: Deformation of Curves and Yakovlev Diagrams\nby Alexios Terezakis
(National and Kapodistrian University of Athens & University of Thessaly)
as part of Greek Algebra & Number Theory Seminar\n\n\nAbstract\nIn this t
alk\, we will explain how a deformation of a curve with a group action can
be translated into studying the integral representations of the group. Su
ch representations are often quite hard to understand and difficult to cla
ssify. In this setting\, we introduce the theory of Yakovlev diagrams and
show how it can be used in our case.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/80/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexandros Galanakis (Bundeswehr University Munich)
DTSTART:20260226T153000Z
DTEND:20260226T163000Z
DTSTAMP:20260404T111212Z
UID:GANT/81
DESCRIPTION:Title: Adelic Eisenstein Classes and Applications to Stickelberger Elements<
/a>\nby Alexandros Galanakis (Bundeswehr University Munich) as part of Gre
ek Algebra & Number Theory Seminar\n\n\nAbstract\nWe construct an adelic r
efinement of Nori’s Eisenstein cohomology classes and their integral ver
sion due to Beilinson\, Kings\, and Levin. This adelic perspective provide
s a natural and unified framework for studying integrality properties of p
artial zeta values and leads to new divisibility results for Stickelberger
elements. This was joint work with Michael Spiess.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/81/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dafni Tsipa (University of the Aegean)
DTSTART:20260326T143000Z
DTEND:20260326T153000Z
DTSTAMP:20260404T111212Z
UID:GANT/82
DESCRIPTION:Title: Residual properties of Generalized Baumslag-Solitar groups\nby Da
fni Tsipa (University of the Aegean) as part of Greek Algebra & Number The
ory Seminar\n\n\nAbstract\nFor a group G let γω(G) denote the intersecti
on of the lower central series and (Np)ω(G) denote the intersection of al
l subgroups whose index is a power of a prime p. The group G is residually
nilpotent if and only if γω(G) is trivial while G is a residually fini
te p-group if and only if (Np)ω(G) is trivial. Thus\, the groups γω(G)
and (Np)ω(G) describe how far G is from being residually nilpotent and b
eing a residually finite p-group respectively. In this talk we will descri
be the Generalized Baumslag-Solitar groups (GBS groups) which are fundamen
tal groups of graphs of groups with infinite cyclic vertex and edge groups
and then we will compute the intersections γω(G) and (Np)ω(G) in the c
ase where the underlying graph is a tree. The results presented are based
on joint work with V. Metaftsis.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/82/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dimitrios Noulas (National and Kapodistrian University of Athens)
DTSTART:20260423T133000Z
DTEND:20260423T143000Z
DTSTAMP:20260404T111212Z
UID:GANT/83
DESCRIPTION:Title: Distortion maps for elliptic curves over finite fields\nby Dimitr
ios Noulas (National and Kapodistrian University of Athens) as part of Gre
ek Algebra & Number Theory Seminar\n\n\nAbstract\nIf P is a torsion point
on an elliptic curve over a finite field\, then a distortion map with resp
ect to P is an endomorphism that maps P outside the cyclic group generated
by P. While initially motivated by questions related to cryptography\, th
e algebraic properties and existence conditions of such maps present an in
teresting problem in its own right\, related to the arithmetic of endomorp
hism rings. In this talk\, we will discuss the arithmetic of distortion ma
ps and provide a criterion for a map to be a distortion map\, as well as a
complete classification regarding their existence over finite fields. Thi
s is joint work with Nikita Andrusov\, Sevag Büyüksimkeşyan\, Fabien Pa
zuki\, Mustafa Umut Kazancıoğlu\, and Jordi Vilà-Casadevall.\n
LOCATION:https://stable.researchseminars.org/talk/GANT/83/
END:VEVENT
END:VCALENDAR