BEGIN:VCALENDAR
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CALSCALE:GREGORIAN
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BEGIN:VEVENT
SUMMARY:Nikolay Grantcharov (University of Chicago)
DTSTART:20201202T163000Z
DTEND:20201202T174500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/1
DESCRIPTION:Title: Finite-dimensional representation theory of the queer Lie supera
lgebra q(n)\nby Nikolay Grantcharov (University of Chicago) as part of
STARS: Superalgebra Theory and Representations Seminar\n\n\nAbstract\nWe
will first describe some classical theory of the queer Lie superalgebras q
(n)\, such as Clifford modules\, (generic) character formula for the irred
ucible representations\, and classification of the blocks of finite-dimens
ional representations. Then we will focus our attention to q(3) and provid
e an explicit description of the Ext-quivers of the blocks. A proof of a `
`virtual'' BGG reciprocity for q(n)\, which then gives the radical filtrat
ions of indecomposable projective objects for q(3)\, will be provided.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kevin Coulembier (University of Sydney)
DTSTART:20201216T080000Z
DTEND:20201216T091500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/3
DESCRIPTION:Title: A semisimple extension of the Takiff superalgebra\nby Kevin
Coulembier (University of Sydney) as part of STARS: Superalgebra Theory an
d Representations Seminar\n\n\nAbstract\nIn this talk\, I will give an ove
rview of the (finite dimensional) representation theory of a particular se
misimple Lie superalgebra. In particular\, I will explain character formu
las\, extension groups\, block decompositions\, invariant theory and Koszu
lity.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thorsten Heidersdorf (Bonn University)
DTSTART:20201209T163000Z
DTEND:20201209T174500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/4
DESCRIPTION:Title: Indecomposable summands in tensor products\nby Thorsten Heid
ersdorf (Bonn University) as part of STARS: Superalgebra Theory and Repres
entations Seminar\n\n\nAbstract\nI will report on some progress to underst
and indecomposable summands in tensor products of irreducible representati
ons of $\\mathfrak{gl}(m|n)$. I will focus on the $\\mathfrak{gl}(m|2)$-ca
se ($m \\geq 2$) which exhibits many features of the general case. The cru
cial tool is the Duflo-Serganova functor and some of its variants.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex Sherman (Ben Gurion University)
DTSTART:20201223T163000Z
DTEND:20201223T174500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/5
DESCRIPTION:Title: Around the classification of semisimple algebraic supergroups\nby Alex Sherman (Ben Gurion University) as part of STARS: Superalgebra
Theory and Representations Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Krishanu Roy (Bar Ilan University)
DTSTART:20201230T163000Z
DTEND:20201230T174500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/6
DESCRIPTION:Title: Pi-systems and closed systems in symmetrizable Kac-Moody algebra
s\nby Krishanu Roy (Bar Ilan University) as part of STARS: Superalgebr
a Theory and Representations Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shifra Reif (Bar-Ilan University)
DTSTART:20210106T233000Z
DTEND:20210107T003000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/7
DESCRIPTION:Title: Grothendieck rings for queer Lie superalgebras\nby Shifra Re
if (Bar-Ilan University) as part of STARS: Superalgebra Theory and Represe
ntations Seminar\n\n\nAbstract\nThe Grothendieck ring of the category of f
inite dimensional representations over a simple Lie algebra can be describ
ed via the character map\, as a ring of functions invariant under the acti
on of the Weyl group. This result was generalized to basic Lie superalgebr
as by A. N. Sergeev and A. P. Veselov with additional invariance condition
s.\n\nIn this talk we will discuss the ring of characters for queer Lie su
peralgebras. In particular\, for the queer Lie supergroup $Q(n)$\, we show
that the ring is isomorphic to the ring of symmetric Laurent polynomials
in $x_1\,...\,x_n$ such that the evaluation $x_1=-x_2=t$ is independent of
$t$. We shall discuss the representation theoretical meaning of this eval
uation.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Volodymyr Mazorchuk (Uppsala University)
DTSTART:20210127T163000Z
DTEND:20210127T174500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/8
DESCRIPTION:Title: Bigrassmannian permutations and Verma modules\nby Volodymyr
Mazorchuk (Uppsala University) as part of STARS: Superalgebra Theory and R
epresentations Seminar\n\n\nAbstract\nIn this talk I will describe how big
rassmannian\npermutations control the socle of the cokernel of\nembeddings
of Verma modules for sl_n. An applciation of\nthis is a description of th
e socle of the cokernel of\nhomomorphisms between Verma modules for the pe
riplective Lie\nsuperalgebra. This is based on two joint works:\none with
Hankyung Ko and Rafael Mrden and another one with\nChih-Whi Chen.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex Sherman (Ben Gurion University)
DTSTART:20210310T171500Z
DTEND:20210310T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/9
DESCRIPTION:Title: The full ghost centre and a projectivity polynomial\nby Alex
Sherman (Ben Gurion University) as part of STARS: Superalgebra Theory and
Representations Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jae-Hoon Kwon (Seoul National University)
DTSTART:20210317T080000Z
DTEND:20210317T091500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/10
DESCRIPTION:Title: A combinatorial character formula for the periplectic Lie super
algebra.\nby Jae-Hoon Kwon (Seoul National University) as part of STAR
S: Superalgebra Theory and Representations Seminar\n\n\nAbstract\nIn this
talk\, we introduce a combinatorial formula for a finite-dimensional irred
ucible representation of the periplectic Lie superalgebra.\nThe irreducibl
e character is given by a cancellation-free alternating sum over the chara
cters of thick or thin Kac modules\, where the highest weights for the Kac
modules appearing here are characterized in terms of a ribbon titling. Th
e formula is obtained by using the result on the decomposition multiplicit
y of a simple module in Kac modules due to Balagovic et al. This is joint
work with B.-H. Hwang (arXiv:2101.05642).\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jon Kujawa (University of Oklahoma)
DTSTART:20210407T161500Z
DTEND:20210407T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/11
DESCRIPTION:Title: Support varieties and complexity for Lie superalgebras\nby
Jon Kujawa (University of Oklahoma) as part of STARS: Superalgebra Theory
and Representations Seminar\n\n\nAbstract\nSupport varieties have long his
tory in modular representation theory and are known to capture important i
nformation. A relevant example is the fact their dimension equals the rat
e of growth of a module's minimal projective resolution (aka the module's
complexity). Motivated by these successes\, Boe\, Kujawa\, and Nakano int
roduced support varieties to the study of complex representations of Lie s
uperalgebras. They are known to contain valuable information but are stil
l mysterious in a number of respects -- including their relationship to co
mplexity. In this talk we will explain explicit computations of both supp
ort varieties and complexity for Lie superalgebras which we think are illu
minating.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chih-Whi Chen (Academia Sinica)
DTSTART:20210421T120000Z
DTEND:20210421T131500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/12
DESCRIPTION:Title: Simple supermodules for classical Lie superalgebras\nby Chi
h-Whi Chen (Academia Sinica) as part of STARS: Superalgebra Theory and Rep
resentations Seminar\n\n\nAbstract\nThe problem of classification of all s
imple modules for a given Lie algebra is rather difficult. Some kind of so
lution exists only for the Lie algebra $\\mathfrak{sl}(2)$ due to Block's
classification theorem. \n\n A finite-dimensional Lie superalgebra $\\math
frak{g}=\\mathfrak{g}_{\\bar 0}\\oplus\\mathfrak{g}_{\\bar 1}$ is called q
uasireductive if $\\mathfrak{g}_{\\bar 0}$ is a reductive Lie algebra and
$\\mathfrak {g}_{\\bar 1}$ is a completely reducible $\\mathfrak {g}_{\\ba
r 0}$-module. In this talk\, we will mainly focus on simple supermodules
for quasireductive type-I Lie superalgebras. We explain the connection b
etween simple supermodules over $\\mathfrak g$ and simple modules over the
underlying Lie algebra $\\mathfrak g_{\\overline 0}$. As an application\,
we classify simple Whittaker supermodules for the type-I Lie superalgebra
s $\\mathfrak{gl}(m|n)$\, $\\mathfrak{osp}(2|2n)$ and $\\mathfrak{pe}(n)$.
\n\n\nThis talk is based on the joint work with Kevin Coulembier and Vol
odymyr Mazorchuk.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nick Davidson (Reed College)
DTSTART:20210512T161500Z
DTEND:20210512T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/13
DESCRIPTION:Title: Type P Webs and Howe Duality\nby Nick Davidson (Reed Colleg
e) as part of STARS: Superalgebra Theory and Representations Seminar\n\n\n
Abstract\nWebs are combinatorially defined diagrams which encode homomorph
isms between tensor products of certain representations of Lie (super)alge
bras. I will describe some recent work which defines webs associated to t
he type P Lie superalgebra\, and then gives a generators-and-relations pre
sentation for the type P enveloping algebra. Using these constructions\,
we deduce an analog of Howe duality in the type P setting.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hadi Salmasian (University of Ottawa)
DTSTART:20210602T163000Z
DTEND:20210602T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/14
DESCRIPTION:Title: Eigenvalues of Capelli operators for superspherical harmonics\,
Deligne's category Rep(O_t)\, and the Dougall-Ramanujan identity\nby
Hadi Salmasian (University of Ottawa) as part of STARS: Superalgebra Theor
y and Representations Seminar\n\n\nAbstract\nGiven a module $V$ of a Lie (
super)algebra $g$ such that $S(V)$ is completely reducible and multiplicit
y-free\, one can define a distinguished basis of "Capelli operators" for t
he algebra of $g$-invariant differential operators on $V$. The "Capelli Ei
genvalue Problem" (CEP) is the problem of computing the eigenvalues of thi
s basis. For reductive Lie algebras\, the CEP was first studied by Kostant
and Sahi\, and then in Sahi's work it culminated in the theory of interpo
lation Jack polynomials. More recently\, Sahi\, Serganova\, and S. solved
the analogous CEP for basic Lie superalgebras.\n\nIn this talk\, we will c
hoose $V$ to be an orthosymplectic superspace and $g:=gosp(V)$ to be the L
ie superalgebra of similitudes of $V$. Then it is known that in general $S
(V)$ is neither completely reducible\, nor multiplicity-free. Nevertheless
\, we show that it is still possible to define a Capelli basis\, and then
we compute two formulas for their eigenvalues. Along the way\, the Dougall
-Ramanujan hypergeometric identity and Deligne's category $Rep(O_t)$ appea
r as pleasant surprises. This talk is based on a joint work with Siddharth
a Sahi and Vera Serganova.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ian Musson (Wisconsin University)
DTSTART:20210630T130000Z
DTEND:20210630T141500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/15
DESCRIPTION:Title: Explicit expressions for Shapovalov elements in Type A\nby
Ian Musson (Wisconsin University) as part of STARS: Superalgebra Theory an
d Representations Seminar\n\n\nAbstract\nhttps://drive.google.com/file/d/1
GrhkZp3qM2jhbJRNcQn5mVejR_Hqgw-B/view?usp=sharing\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shun-Jen Cheng (Academia Sinica)
DTSTART:20210707T070000Z
DTEND:20210707T083000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/16
DESCRIPTION:Title: Representation theory of a semisimple extension of the Takiff s
uperalgebra\nby Shun-Jen Cheng (Academia Sinica) as part of STARS: Sup
eralgebra Theory and Representations Seminar\n\n\nAbstract\nIn this talk w
e shall discuss the representation theory of a semisimple extension of a T
akiff superalgebra. We determine the blocks in both the finite-dimensional
and BGG module categories and also classify the Borel subalgebras. We als
o give a description of all extension groups between two finite-dimensiona
l simple objects. This is a joint work with Kevin Coulembier.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Graham Hawkes (Ben-Gurion University)
DTSTART:20210721T080000Z
DTEND:20210721T090000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/17
DESCRIPTION:Title: Schubert Polynomials of Type B\nby Graham Hawkes (Ben-Gurio
n University) as part of STARS: Superalgebra Theory and Representations Se
minar\n\nLecture held in Also LIVE at Weizmann Institute\, Room 1.\n\nAbst
ract\nWhen Kirillov and Fomin began searching for what might be the natur
al hyperoctohedral version of the type A Schubert polynomials\, they set o
ut a series of properties that they believed these poynomials ought to hav
e. These consist in (1) satisfying the recurrence relations with divided
difference operators\, (2) having nonnegative coeffiecients\, and (3) prod
ucing the type C Stanley symmetric function as a certain limit. \n\nWhile
satisfying most of these properties in addition to others\, the polynomial
s defined\, unfortunatley\, do not satisfy the divided difference relation
for the special generator of the hyperoctahedral group. Moreover\, while
type A Schubert polynomials can in fact be easily constructed via succesi
vely applying divided difference to a special starting monomial (namely\,
$x_1^0x_2^1\\cdots x_n^{n-1}$) this is not true of their type B candidate
(in fact this follows from the statement above).\n\nWe introduce a differe
nt candidate for the octahedral Schubert polynomial\, constructing it dir
ectly from the monomial $x_1^1x_2^3\\cdots x_n^{2n-1}$ via divided differe
nce operators. By construction the result satisfies propery (1) above. C
onjecturely it also satisfies (2) and (3) and we have verified these conje
ctures up to $n=4$. \n\nIn this talk we review the results for the type A
case and show what roadblocks appear if one tries to adapt the proofs in t
he type A case to the type B case. We also mention some partial results w
e believe may be useful in eventually proving the conjecture.\n\nThis is a
a special talk in algebraic combinatorics. We will do our best to show t
his talk via ZOOM\, at the usual address:\n\nhttps://us02web.zoom.us/j/881
89258443?pwd=S3JLcElXTUpadktqZ0VLWHNmVXdiQT09\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shrawan Kumar (UNC)
DTSTART:20211110T171500Z
DTEND:20211110T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/18
DESCRIPTION:Title: ROOT COMPONENTS FOR TENSOR PRODUCT OF AFFINE KAC-MOODY LIE ALGE
BRA MODULES\nby Shrawan Kumar (UNC) as part of STARS: Superalgebra The
ory and Representations Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gus Lehrer (University of Sydney)
DTSTART:20211124T080000Z
DTEND:20211124T091500Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/19
DESCRIPTION:Title: Invariant theory for the orthosymplectic super group.\nby G
us Lehrer (University of Sydney) as part of STARS: Superalgebra Theory and
Representations Seminar\n\n\nAbstract\nWe show how invariants of the orth
osymplectic super group may be converted into invariants of super $GL_n$\,
using algebraic geometric arguments. By this means\, we obtain precise ve
rsions of the first and second fundamental theorems of invariant theory fo
r these groups\, despite the absence of semisimplicity.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alistair Savage (University of Ottawa)
DTSTART:20211208T171500Z
DTEND:20211208T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/20
DESCRIPTION:Title: Affine oriented Frobenius Brauer categories\nby Alistair Sa
vage (University of Ottawa) as part of STARS: Superalgebra Theory and Repr
esentations Seminar\n\n\nAbstract\nTo any Frobenius superalgebra $A$ we as
sociate an oriented Frobenius Brauer category and an affine oriented Frobe
nius Brauer category. We define natural actions of these categories on ca
tegories of supermodules for general linear Lie superalgebras $\\mathfrak{
gl}_{m|n}(A)$ with entries in $A$. These actions generalize those on modu
le categories for general linear Lie superalgebras and queer Lie superalge
bras\, which correspond to the cases where $A$ is the ground field and the
two-dimensional Clifford superalgebra\, respectively.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexandra Utiralova (MIT)
DTSTART:20220112T171500Z
DTEND:20220112T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/21
DESCRIPTION:Title: Harish-Chandra bimodules in complex rank\nby Alexandra Utir
alova (MIT) as part of STARS: Superalgebra Theory and Representations Semi
nar\n\n\nAbstract\nDeligne tensor categories are defined as an interpolati
on of the categories of representations of groups GL_n\, O_n\, Sp_{2n} or
S_n to the complex values of the parameter n. One can extend many classica
l representation-theoretic notions and constructions to this context. Thes
e complex rank analogs of classical objects provide insights into their st
able behavior patterns as n goes to infinity.\nI will talk about some of m
y results on Harish-Chandra bimodules in Deligne categories. It is known t
hat in the classical case simple Harish-Chandra bimodules admit a classifi
cation in terms of W-orbits of certain pairs of weights. However\, the not
ion of weight is not well-defined in the setting of Deligne categories. I
will explain how in complex rank the above-mentioned classification transl
ates to a condition on the corresponding (left and right) central characte
rs.\nAnother interesting phenomenon arising in complex rank is that there
are two ways to define Harish-Chandra bimodules. That is\, one can either
require that the center acts locally finitely on a bimodule M or that M ha
s a finite K-type. The two conditions are known to be equivalent for a sem
i-simple Lie algebra in the classical setting\, however\, in Deligne categ
ories that is no longer the case. I will talk about a way to construct exa
mples of Harish-Chandra bimodules of finite K-type using the ultraproduct
realization of Deligne categories.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Volodymyr Mazorchuk (Uppsala University)
DTSTART:20220119T171500Z
DTEND:20220119T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/22
DESCRIPTION:Title: Category O is Auslander regular\nby Volodymyr Mazorchuk (Up
psala University) as part of STARS: Superalgebra Theory and Representation
s Seminar\n\n\nAbstract\nIn this talk I will prove that category O and its
several generalizations are Auslander regular\, which is a condition\ndef
ined in terms of homological dimensions of structural modules.\n\nThis is
a joint work with Hankyung Ko and Rafael Mrden (answering a question by Re
ne Marczinzik).\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ivan Penkov (Jacobs University)
DTSTART:20220202T171500Z
DTEND:20220202T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/23
DESCRIPTION:Title: Some results and open problems on representations of classical
Lie (super)algebras at infinity\nby Ivan Penkov (Jacobs University) as
part of STARS: Superalgebra Theory and Representations Seminar\n\n\nAbstr
act\nI will describe known results and open problems concerning various re
presentation categories of classical Lie (super)algebras\nat infinity\, an
d will pose the problem of classifying primitive ideals of certain envelop
ing (super)algebras\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrew Snowden (University of Michigan)
DTSTART:20220302T171500Z
DTEND:20220302T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/24
DESCRIPTION:Title: Cohomology of flag supermanifolds and resolutions of determinan
tal ideals\nby Andrew Snowden (University of Michigan) as part of STAR
S: Superalgebra Theory and Representations Seminar\n\n\nAbstract\nI will e
xplain joint work with Steven Sam in which we completely compute the coher
ent cohomology of super Grassmannians\, and some other flag supervarieties
. Our main observation is that these groups are\nclosely related to the fr
ee resolutions of (certain generalizations of) determinantal ideals.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex Sherman (Ben Gurion University)
DTSTART:20211020T161500Z
DTEND:20211020T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/25
DESCRIPTION:Title: Minicourse on Duflo-Serganova functors (part 1)\nby Alex Sh
erman (Ben Gurion University) as part of STARS: Superalgebra Theory and Re
presentations Seminar\n\n\nAbstract\nAbout the course:\nGiven an odd eleme
nt x in a Lie superalgebra g satisfying [x\, x] = 0\, we have that x^2 = 0
in the\nuniversal enveloping algebra of g\, and so for every g-module M\,
we can define the cohomology\nDS_x (M) := Ker (x) / Im(x).\nIn fact\, DS(
M) is a module for the Lie superalgebra\ng_x := DS_x (g) = Ker ad(x) / Im
ad(x)\,\nwhich is a Lie superalgebra of smaller rank than g. \nFor example
\, if g = gl(m|n) and x is a root vector\, then g_x = gl(m − 1|n − 1).
\nDuflo and Serganova defined the functor DS_x from the category of g-mod
ules to the category of g_x-modules which is now called the Duflo–Sergan
ova functor. This minicourse will give an overview of the theory of Duflo
–Serganova functors and the recent advances in their study.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex Sherman and Crystal Hoyt (Ben Gurion University and Bar Ilan
University)
DTSTART:20211027T161500Z
DTEND:20211027T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/26
DESCRIPTION:Title: Minicourse on Duflo-Serganova functors (part 2)\nby Alex Sh
erman and Crystal Hoyt (Ben Gurion University and Bar Ilan University) as
part of STARS: Superalgebra Theory and Representations Seminar\n\n\nAbstra
ct\nAbout the course:\nGiven an odd element x in a Lie superalgebra g sati
sfying [x\, x] = 0\, we have that x^2 = 0 in the\nuniversal enveloping alg
ebra of g\, and so for every g-module M\, we can define the cohomology\nDS
_x (M) := Ker (x) / Im(x).\nIn fact\, DS(M) is a module for the Lie supera
lgebra\ng_x := DS_x (g) = Ker ad(x) / Im ad(x)\,\nwhich is a Lie superalge
bra of smaller rank than g. \nFor example\, if g = gl(m|n) and x is a root
vector\, then g_x = gl(m − 1|n − 1). \nDuflo and Serganova defined th
e functor DS_x from the category of g-modules to the category of g_x-modul
es which is now called the Duflo–Serganova functor. This minicourse will
give an overview of the theory of Duflo–Serganova functors and the rece
nt advances in their study.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex Sherman and Crystal Hoyt (Ben Gurion University and Bar Ilan
University)
DTSTART:20211103T171500Z
DTEND:20211103T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/27
DESCRIPTION:Title: Minicourse on Duflo-Serganova functors (part 3)\nby Alex Sh
erman and Crystal Hoyt (Ben Gurion University and Bar Ilan University) as
part of STARS: Superalgebra Theory and Representations Seminar\n\n\nAbstra
ct\nAbout the course:\nGiven an odd element x in a Lie superalgebra g sati
sfying [x\, x] = 0\, we have that x^2 = 0 in the\nuniversal enveloping alg
ebra of g\, and so for every g-module M\, we can define the cohomology\nDS
_x (M) := Ker (x) / Im(x).\nIn fact\, DS(M) is a module for the Lie supera
lgebra\ng_x := DS_x (g) = Ker ad(x) / Im ad(x)\,\nwhich is a Lie superalge
bra of smaller rank than g. \nFor example\, if g = gl(m|n) and x is a root
vector\, then g_x = gl(m − 1|n − 1). \nDuflo and Serganova defined th
e functor DS_x from the category of g-modules to the category of g_x-modul
es which is now called the Duflo–Serganova functor. This minicourse will
give an overview of the theory of Duflo–Serganova functors and the rece
nt advances in their study.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Elena Poletaeva (UT Rio Grande Valley)
DTSTART:20220309T171500Z
DTEND:20220309T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/28
DESCRIPTION:Title: On representations of finite $W$-algebras and super Yangians\nby Elena Poletaeva (UT Rio Grande Valley) as part of STARS: Superalgebr
a Theory and Representations Seminar\n\n\nAbstract\nA finite $W$-algebra i
s certain associative algebra attached to a pair $(\\mathfrak{g}\, e)$\,
where\n$\\mathfrak{g}$ is a complex semisimple Lie algebra and $e\\in \\ma
thfrak{g}$ is a nilpotent element.\nIt is a generalization of the universa
l enveloping algebra $U(\\mathfrak{g})$.\nWe classify irreducible represen
tations of finite $W$-algebra for the queer Lie superalgebra $Q(n)$ associ
ated with the regular even nilpotent coadjoint orbits.\nWe use this result
to obtain a classification of irreducible finite-dimensional representati
ons of the super Yangian $YQ(1)$.\n\n\nIt is a joint work with V. Serganov
a.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:L. Andrew Jenkins (University of Georgia)
DTSTART:20211117T171500Z
DTEND:20211117T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/29
DESCRIPTION:Title: The nilpotent cone for classical simple Lie superalgebras\n
by L. Andrew Jenkins (University of Georgia) as part of STARS: Superalgebr
a Theory and Representations Seminar\n\n\nAbstract\nMany aspects of the re
presentation theory of a Lie algebra and its associated algebraic group ar
e governed by the geometry of their nilpotent cone. In this talk\, we will
introduce an analogue of the nilpotent cone $\\mathcal{N}$ for Lie supera
lgebras and show that for a simple classical Lie superalgebra the number o
f nilpotent orbits is finite. We will also show that the commuting variety
$\\mathcal{X}$ described by Duflo and Serganova\, which has applications
in the study of the finite dimensional representation theory of Lie supera
lgebras\, is contained in $\\mathcal{N}$. Consequently\, the finiteness re
sult on $\\mathcal{N}$ generalizes and extends the work on the commuting v
ariety. For the general linear Lie superalgebra $\\mathfrak{gl}(m|n)$\, we
will also discuss more detailed geometric results of $\\mathcal{N}$. In p
articular\, we compute the dimensions of $\\mathcal{N}$ and the centralize
r of a nilpotent orbit\, describe the irreducible components of $\\mathcal
{N}$\, and show that $\\mathcal{N}$ is a complete intersection. This is jo
int work with Daniel Nakano from the University of Georgia.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Crystal Hoyt (Bar Ilan University)
DTSTART:20211229T123000Z
DTEND:20211229T133000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/30
DESCRIPTION:Title: Representations of the Cartan Type Lie superalgebra W(infty)\nby Crystal Hoyt (Bar Ilan University) as part of STARS: Superalgebra Th
eory and Representations Seminar\n\n\nAbstract\nThe Lie superalgebra W(inf
ty) is the direct limit of finite-dimensional Cartan type Lie superalgebr
as W(n) as n goes to infinity. In this talk\, we will discuss Z-graded mod
ules over W(infty). We introduce a category T_W of W(infty)-modules which
is closely related to the category T_gl of tensor sl(infty)-modules introd
uced and studied by Dan-Cohen\, Serganova and Penkov. We show that each si
mple module in T_W is isomorphic to the unique simple quotient of a module
induced from a simple module in T_gl\, and vice versa. This is joint work
with Lucas Calixto.\n\nThis talk is part of the Winter STARS workshop. Th
e webpage of the workshop can be found here:\nhttps://innaentova.wixsite.c
om/winterstars2021/\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thorsten Heidersdorf (Bonn University)
DTSTART:20211229T152000Z
DTEND:20211229T162000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/31
DESCRIPTION:Title: Indecomposable summands in tensor products\nby Thorsten Hei
dersdorf (Bonn University) as part of STARS: Superalgebra Theory and Repre
sentations Seminar\n\n\nAbstract\nI will give an explicit description of t
he indecomposable summands in a tensor power\n\nV^{\\otimes r} where V den
otes the standard representation of the orthosymplectic supergroup OSp(m|2
n).\nAt the end I will ask what we know in general about the structure of
the indecomposable summands in a tensor product decomposition L(\\lambda)
\\otimes L(\\mu) for irreducible representations of a supergroup such as G
L(m|n).\n\nThis talk is part of the Winter STARS workshop. The webpage of
the workshop can be found here:\nhttps://innaentova.wixsite.com/winterstar
s2021/\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vadim Schechtman (Institut de Mathématiques de Toulouse)
DTSTART:20211229T140000Z
DTEND:20211229T150000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/32
DESCRIPTION:Title: PROBs and sheaves\nby Vadim Schechtman (Institut de Mathém
atiques de Toulouse) as part of STARS: Superalgebra Theory and Representat
ions Seminar\n\n\nAbstract\nI propose to explain how certain universal bia
lgebra allows us to give a linear algebra description of categories of per
verse sheaves over all symmetric powers of the complex plane\, smooth alon
g the diagonal stratification. This bialgebra is closely related to"contin
gency tables" introduced by Karl Pearson more than one hundred years ago.\
n\nThis is a joint work with Mikhail Kapranov.\n\nThis talk is part of the
Winter STARS workshop. The webpage of the workshop can be found here:\nht
tps://innaentova.wixsite.com/winterstars2021/\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aleksandr Sergeev (Saratov State University)
DTSTART:20220323T161500Z
DTEND:20220323T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/33
DESCRIPTION:Title: Canonical bilinear form and Euler characters\nby Aleksandr
Sergeev (Saratov State University) as part of STARS: Superalgebra Theory a
nd Representations Seminar\n\n\nAbstract\nAn explicit formula for the cano
nical bilinear form on the Grothendieck ring of the Lie supergroup GL(n\,
m) is given. As an application we get an algorithm for the decomposition E
uler characters in terms of charactrers of irreducible modules in the cate
gory of partially polynomial modules.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vladimir Stukopin (Moscow Institute of Physics and Technology)
DTSTART:20220330T161500Z
DTEND:20220330T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/34
DESCRIPTION:Title: Hopf superalgebra structures on quantum superalgebras\, super Y
angians and quantum loop superalgebras\nby Vladimir Stukopin (Moscow I
nstitute of Physics and Technology) as part of STARS: Superalgebra Theory
and Representations Seminar\n\n\nAbstract\nI am going to tell about descri
ption and classification of Hopf superalgebras structures and quisitriangu
lar structures on quantum superalgebras\, super Yangians and quantum loop
superalgebras. It will be consider relation between Hopf superalgebra stru
ctures and construction of Weyl groupoid in detail in the case of quantum
superalgebra $U_q(sl(m\,n))$. I will also tell about generalization of thi
s construction on the case infinite dimensional quantum superalgebras such
that super Yangians and quantum loop superalgebras. I also describe the
structures of tensor categories on Yangian and quantum loop superalgebra c
ategories of representations\, which are analogues of the category $\\math
frak{O}$ and investigate the relation between them. It will be construct
an isomorphism in the category of Hopf superalgebras between the completio
n of the super Yangian and of the completion quantum loop superalgebra. A
theorem on the equivalence of tensor categories of modules over the super
Yangian and the quantum loop superalgebra is formulated also. It will be a
lso described relation between different quasitriangular structures (unive
rsal R-matrices) on the super Yangians and quantum loop superalgebras\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Weiqiang Wang (University of Virginia)
DTSTART:20220727T161500Z
DTEND:20220727T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/35
DESCRIPTION:Title: Kazhdan-Lusztig bases and quantum Schur dualities ABC\nby W
eiqiang Wang (University of Virginia) as part of STARS: Superalgebra Theor
y and Representations Seminar\n\n\nAbstract\nThe type A quantum Schur dual
ity (due to Jimbo) concerns about commuting actions on a tensor space of a
quantum group and a Hecke algebra of type A. Several years ago\, a dualit
y between a Hecke algebra of type B and an i-quantum group arising from qu
antum symmetric pairs was obtained by Bao and myself (and Watanabe in uneq
ual parameters). Both dualities are intimately related to canonical bases
and (super) Kazhdan-Lusztig theory of type ABC(D). In this talk\, I will e
xplain a unification of both dualities involving i-quantum groups\, which
leads to a generalization of Kazhdan-Lusztig bases of type B. This is join
t work with Yaolong Shen (Virginia).\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Nakano (University of Georgia)
DTSTART:20220427T161500Z
DTEND:20220427T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/36
DESCRIPTION:Title: Sheaf cohomology via detecting subalgebras and BBW parabolic su
balgebras\nby Daniel Nakano (University of Georgia) as part of STARS:
Superalgebra Theory and Representations Seminar\n\n\nAbstract\nFifteen yea
rs ago\, Boe\, Kujawa and the speaker introduced the concept of detecting
subalgebras for classical simple Lie superalgebras. These algebras were co
nstructed by using ideas from geometric invariant theory. More recently\,
D. Grantcharov\, N. Grantcharov\, Wu and the speaker introduced the concep
t of a BBW parabolic subalgebra. Given a ${\\mathfrak g}$\, one has a tria
ngular decomposition ${\\mathfrak g}={\\mathfrak n}^{-}\\oplus {\\mathfrak
f} \\oplus {\\mathfrak n}^{+}$ with ${\\mathfrak b}={\\mathfrak f}\\oplus
{\\mathfrak n}^{-}$ where ${\\mathfrak f}$ is a detecting subalgebra and
${\\mathfrak b}$ is a BBW parabolic subalgebra. This holds for all classic
al ``simple’’ Lie superalgebras\, and one can view ${\\mathfrak f}$ as
an analog of the maximal torus\, and ${\\mathfrak b}$ like a Borel subalg
ebra. This setting also provide a useful method to define semisimple eleme
nts and nilpotent elements\, and to compute various sheaf cohomology group
s $R^{\\bullet}\\text{ind}_{B}^{G} (-)$. \n\n \n\nIn this talk\, I will pr
ovide a systematic treatment that allows us to study the behavior of these
cohomology groups $H^{\\bullet}(\\lambda)=R^{\\bullet}\\text{ind}_{B}^{G}
L_{\\mathfrak f}(\\lambda)$ where $L_{\\mathfrak f}(\\lambda)$ is an irre
ducible representation for the detecting subalgebra ${\\mathfrak f}$. In p
articular\, we prove an analog of \n\nKempf's vanishing theorem and the Bo
tt-Borel-Weil theorem for large weights\, and investigate the structure of
$H^{1}(\\lambda)$. \n\n \n\nThis talk represents joint work with David G
alban.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christopher Drupieski (DePaul University)
DTSTART:20220511T161500Z
DTEND:20220511T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/37
DESCRIPTION:Title: Support varieties for Lie superalgebras and finite supergroup s
chemes\nby Christopher Drupieski (DePaul University) as part of STARS:
Superalgebra Theory and Representations Seminar\n\n\nAbstract\nSupport va
rieties are tools that assign to each representation of a group G (or more
generally\, a Hopf algebra) a corresponding geometric invariant. Often\,
the ambient geometric space is the spectrum of the cohomology ring of G\,
and the geometric invariants are defined in terms of the action of the coh
omology ring on other extension groups. These geometric invariants may the
n encode interesting aspects of the module category\, such as whether or n
ot a module is projective. In some situations\, support varieties are know
n to classify the thick tensor ideals in the ambient stable module categor
y. In this talk I’ll give an overview of support varieties in the contex
t of Lie superalgebras (both restricted and non-restricted) and finite sup
ergroup schemes over fields of positive characteristic.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michael Finkelberg (National Research University Higher School of
Economics)
DTSTART:20220601T132000Z
DTEND:20220601T142000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/38
DESCRIPTION:by Michael Finkelberg (National Research University Higher Sch
ool of Economics) as part of STARS: Superalgebra Theory and Representation
s Seminar\n\n\nAbstract\nThis is part of the Summer STARS workshop.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ian Musson (University of Wisconsin-Milwaukee)
DTSTART:20220406T161500Z
DTEND:20220406T173000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/39
DESCRIPTION:Title: On the geometry of algebras related to the Weyl groupoid\nb
y Ian Musson (University of Wisconsin-Milwaukee) as part of STARS: Superal
gebra Theory and Representations Seminar\n\n\nAbstract\nLet $\\mathtt{k}$
be an algebraically closed field of characteristic zero. Let $\\mathfrak{
g}$ be a finite dimensional classical simple Lie superalgebra over $\\math
tt{k}$ or $\\mathfrak{gl}(m\,n)$. In the case that $\\mathfrak{g}$ is a Ka
c-Moody algebra of finite type with set of roots $R$\, Sergeev and Veselo
v introduced the \nWeyl groupoid $\\mathfrak{W}(R)$\, which has significan
t connections with the representation theory of $\\mathfrak{g}$. Let $\\ma
thfrak{h}$\, $W$\, $Z(\\mathfrak{g})$ and $G_0$ be a Cartan subalgebra of
$\\mathfrak{g}_0$\, the Weyl group of $\\mathfrak{g}_0$\, the center of $U
(\\mathfrak{g})$ respectively and a connected\, simply connected algebraic
group with Lie $G_0 =\\mathfrak{g}_0$. There are two important\ncommutati
ve algebras related to $\\mathfrak{W}(R)$. Namely\n \n\n$\\bullet$ The im
age $I(\\mathfrak{h})$ of the injective Harish-Chandra map $Z(\\mathfrak{g
})\\longrightarrow S(\\mathfrak{h})^W$.\n\n\n$\\bullet$ The supercharacter
$\\Z$-algebra $J(\\mathfrak{g})$ of finite dimensional representations of
$\\mathfrak{g}$.\n\n\nLet $\\mathcal A = \\mathcal A(\\mathfrak{g})$ be d
enote either $I(\\mathfrak{h})$ or $J(\\mathfrak{g}) \\otimes_{\\Z}\\matht
t{k}$. \nThe purpose of this talk \n is to investigate the algebraic geom
etry of $\\mathcal A.$\n As a work in progress we give compelling eviden
ce for two geometric assertions. \nFirst\, the algebra $\\mathcal A$ satis
fies \na Nullstellensatz. (If $\\mathcal A = I(\\mathfrak{h})$\, we ass
ume $\\mathfrak{g} \\neq P(n)$). This gives a bijection between radical i
deals in $\\mathcal A$ and superalgebraic sets (zero loci of such ideals).
\nThe Nullstellensatz is proved using the Duflo-Serganova functor which i
nduces a map $\\mathcal A(\\mathfrak{g})\\longrightarrow\\mathcal A(\\math
frak{g}_x)$ where \n$\\mathfrak{g}_x$ is a Lie superalgebra of lower rank.
\n\n Secondly\, let $\\mathbb{T}$ be a maximal torus in $G_0$. Then \nther
e are categorical and geometric quotients in the category of $\\mathtt{k}
$-schemes\n$$\\mathfrak{h}^*\\longrightarrow \\mathfrak{h}^*/\\mathfrak{W}
^c\\cong\\operatorname{Spec } I(\\mathfrak{h}) \\text{ and }\\mathbb{T} \
\longrightarrow \\mathbb{T}/\\mathfrak{W}_*^c\\cong\\operatorname{Spec }
J(\\mathfrak{g}) \\otimes_{\\mathbb Z} \\mathtt{k}.$$ Here $\\mathfrak{W}^
c \\text{ and } \\mathfrak{W}_*$ are certain continuous versions of the We
yl groupoid.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Johannes Flake (MPI Bonn)
DTSTART:20221207T170000Z
DTEND:20221207T183000Z
DTSTAMP:20260422T230718Z
UID:STARS_BGU_BIU_WIS/40
DESCRIPTION:Title: Interpolating tensor categories and their Grothendieck rings\nby Johannes Flake (MPI Bonn) as part of STARS: Superalgebra Theory and
Representations Seminar\n\n\nAbstract\nWe will review some new and old fam
ilies of (pseudo-)tensor categories which interpolate categories of repres
entations\, like those of symmetric or orthosymplectic groups\, including
Khovanov-Sazdanovic's cobordism categories and several interpolation categ
ories introduced by Deligne. We will then describe a general technique to
determine the indecomposable objects and an associated graded version of t
he Grothendieck ring of such categories\, and discuss the concrete results
in some interesting examples. This is based on joint work with Robert Lau
gwitz and Sebastian Posur.\n
LOCATION:https://researchseminars.org/talk/STARS_BGU_BIU_WIS/40/
END:VEVENT
END:VCALENDAR