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CALSCALE:GREGORIAN
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TZID:Europe/Vienna
BEGIN:DAYLIGHT
DTSTART:20250330T030000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
TZNAME:CEST
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DTSTART:20251026T020000
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TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
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BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:66cd8d1bdd8ec718060628@ist.ac.at
DTSTART:20240924T163000
DTEND:20240924T173000
DESCRIPTION:Speaker: Jan Philip Solovej\nhosted by Robert Seiringer\nAbstra
ct: For a group G we study quantum channels\, i.e.\, completely positive t
race preserving maps between operators on irreducible unitary representati
ons of the group that intertwine the group action\, i.e.\, are eqivariant.
We will mainly focus on G=SU(2) but also discuss SU(d) for d>2. It turns
out that the set of equivariant SU(2) channels forms a finite dimensional
simplex and we will describe the critical points and give several ways to
represent them. Using majorization we will determine the minimal output en
tropy of two of these extremal channels. Generalizations to SU(2) and seve
ral open questions will be discussed
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Jan Philip Solovej: Symmetry preserving quantum channels and their
minimal output entropy
URL:https://talks-calendar.ista.ac.at/events/5186
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:6690d89acd81a384206617@ist.ac.at
DTSTART:20241001T163000
DTEND:20241001T173000
DESCRIPTION:Speaker: Andrew Campbell\nhosted by Laszlo Erdös\nAbstract: We
will discuss two conjectures for entire functions with real roots. The fi
rst\, referred to as Cosine Universality\, asserts that the roots become p
erfectly spaced in the limit of repeated differentiation\, under very mild
assumptions on the original function. The second conjecture\, known as He
rmite Universality\, asserts that for an even entire function $f$ certain
polynomials associated to $f$\, known as the Jensen polynomials\, should c
onverge to Hermite polynomials after an appropriate centering and re-scali
ng under the same assumptions as Cosine Universality. Specifically\, we wi
ll see the surprising role random matrix theory plays in proving these con
jectures for even functions. Using the recently developed theory of finite
free probability we will translate these universality principles into pro
babilistic limit theorems which are roughly equivalent to averaging sums o
f random matrices. This talk will serve as an introduction to finite free
probability. Based on joint work with Sean O'Rourke and David Renfrew.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Andrew Campbell: Finite free probability and universality principle
s for roots of entire functions
URL:https://talks-calendar.ista.ac.at/events/5236
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:648ae475134e6820189361@ist.ac.at
DTSTART:20241003T130000
DTEND:20241003T150000
DESCRIPTION:Speaker: Hiraku Nakajima\nhosted by Tamas Hausel\nAbstract: The
S-dual (G∨M∨) of the pair (GM) of a smooth affine algebraic sympl
ectic manifold M with hamiltonian action of a complex reductive group G
was introduced implicitly in [arXiv:1706.02112 (https://arxiv.org/abs/17
06.02112)] and explicitly in [arXiv:1807.09038 (https://arxiv.org/abs/1807
.09038)] under the cotangent type assumption. The definition was a modific
ation of the definition of Coulomb branches of gauge theories in [arXiv:16
01.03586 (https://arxiv.org/abs/1601.03586)]. It was motivated by the S-du
ality of boundary conditions of 4-dimensional N=4 super Yang-Mills theor
y\, studied by Gaiotto and Witten [arXiv:0807.3720 (https://arxiv.org/abs/
0807.3720)]. It is also relevant to the relative Langlands duality propose
d by Ben-Zvi\, Sakellaridis and Venkatesh. In this article\, we review the
definition and properties of S-dual.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Hiraku Nakajima: S-dual of Hamiltonian G spaces and relative Langla
nds duality
URL:https://talks-calendar.ista.ac.at/events/5221
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:648ae475140fc941027991@ist.ac.at
DTSTART:20241010T130000
DTEND:20241010T150000
DESCRIPTION:Speaker: Sun Woo Park\nhosted by Tim Browning\nAbstract: Let $K
= \\mathbb{F}_q(t)$ be the global function field of characteristic coprim
e to $2$ and $3$. Let $E$ be a non-isotrivial elliptic curve over $K$. Fix
a prime number $l$ such that the primitive $l$-th roots of unity $\\mu_l$
is contained in $\\mathbb{F}_q$. Let $L$ be a $\\mathbb{Z}/l\\mathbb{Z}$
geometric Galois extension over $K$. We will focus on utilizing the Grothe
ndieck-Lefschetz trace formula to compute a lower bound on the probability
that the rank of $E(L)$ is equal to the rank of $E(K)$. If time allows\,
we will also explore how one can combine a probabilistic approach to obtai
n new geometric insights on the cohomology groups of some Hurwitz spaces.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Sun Woo Park: On Selmer groups of cyclic twist families of elliptic
curves over global function fields
URL:https://talks-calendar.ista.ac.at/events/5199
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:648ae47514d08087369894@ist.ac.at
DTSTART:20241017T130000
DTEND:20241017T150000
DESCRIPTION:Speaker: George Lusztig\nhosted by Tamas Hausel\nAbstract: (I)
Fourier transform as a linear map from L^2(R) to L^2(R) has been diagonali
zed by Hermite in the late 1800's using Hermite polynomials.We are interes
ted in the Fourier transform F on the C-vector space of functions on a sym
plectic vector space over the field with two elements. We show that the fo
llowing substitute of Hermite's resultholds: there is a remarkable C-basis
of this vector space in which F acts as a triangular matrix.(II) Let k_p
be an algebraically closed field of characteristic p and let G_p be a redu
ctive connected group over k_p of type independent of p\; let W be the Wey
l group of G_p. We define a partition of G_p into finitely many strata. Ea
ch stratum is a union of conjugacy classes of fixed dimension of G_p. The
set of strata is independent of p.It can be viewed as an enlargement of th
e set of unipotent classes of G_p. It can be identified with the image of
a certain map from the set of conjugacy classes in W to the set of irreduc
ible representations of W.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:George Lusztig: (I) Fourier transform as a triangular matrix / (II)
Strata in reductive groups
URL:https://talks-calendar.ista.ac.at/events/5248
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:66d57d0151a4d896449853@ist.ac.at
DTSTART:20241021T154500
DTEND:20241021T164500
DESCRIPTION:Speaker: Mariya Shcherbina\nhosted by Laszlo Erdös\, Jan Maas\
nAbstract: We apply the SUSY method to derive integral representations for
the correlation functions of characteristic polynomials of Hermitian and
non-Hermitian random band matrices. The structure of the obtained formulas
allows us to apply the transfer operator approach in the 1D case. Thus\,
the analysis of the correlation function is replaced by the spectral analy
sis of some non-self-adjoint integral operator. The results of the analysi
s give us an understanding of the mechanism of the transition from the "lo
calized" to "delocalized spectral behavior of one-dimensional band matrice
s.
LOCATION:Central Bldg / O1 / Mondi 2 (I01.O1.008)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Mariya Shcherbina: Transfer operator approach to 1D random band mat
rices
URL:https://talks-calendar.ista.ac.at/events/5198
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:66d57d1857b75775530853@ist.ac.at
DTSTART:20241021T170000
DTEND:20241021T180000
DESCRIPTION:Speaker: Misha Basok\nhosted by Laszlo Erdös\, Jan Maas\nAbstr
act: In 2013 Miller\, Watson and Wilson introduced the notion of a nesting
field associated with a conformal loop ensemble (CLE). The nesting field
is supposed to count the number of CLE loops surrounding a given point min
us its expectation\; to define this field rigorously\, they proved that th
e number of CLE loops surrounding a disc of radius epsilon minus its expec
tation\, considered as a function of the center of the disc\, converges in
the space of distributions as epsilon tends to zero\, and the limit is co
nformally invariant. We consider a similar nesting field defined with resp
ect to the double-dimer loop ensemble\, i.e. the loop ensemble that appear
s when one superimposes two independent dimer configurations. As this loop
ensemble is conjectured to converge to CLE(4) in the scaling limit\, one
can expect the corresponding behaviour of the nesting field. In this talk
I want to report on the following two results concerning the double-dimer
nesting field in the upper half-plane: Local behaviour: we prove that\, fo
r any fixed point in the upper half-plane\, the number of double-dimer loo
ps surrounding this point minus its expectation converges to a normal dist
ribution if rescaled properly. Note that the same statement for CLE loops
follows easily from conformal invariance.Global behaviour: building on the
results of Kenyon\, Dubedat and B-Chelkak we prove that double-dimer nest
ing fields converge to the nesting field of CLE(4).Based on the joint work
with Konstantin Izyurov (University of Helsinki).
LOCATION:Central Bldg / O1 / Mondi 2 (I01.O1.008)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Misha Basok: Nesting of double-dimer loops and CLE(4)
URL:https://talks-calendar.ista.ac.at/events/5347
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:648ae47515930919175224@ist.ac.at
DTSTART:20241023T140000
DTEND:20241023T160000
DESCRIPTION:Speaker: Alexandra Florea\nhosted by Tim Browning\nAbstract: I
will talk about the negative moments of the Riemann zeta function\, both c
ontinuous and discrete\, based on joint works with Bui\, Keating and Milin
ovich. I will explain how to obtain progress towards a conjecture of Gonek
on negative moments\, when the shift of the negative zeta function is "sm
all" (going to 0 with t). When we are integrating from T to 2T\, and the s
hift is less than 1/(log T)\, we also discuss some conjectures based on ra
ndom matrix theory and some heuristic number theoretic arguments which pre
dict certain transition regimes in the asymptotic formulas.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Alexandra Florea: Negative moments of the Riemann zeta function
URL:https://talks-calendar.ista.ac.at/events/5320
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:648ae4751654b012976680@ist.ac.at
DTSTART:20241031T130000
DTEND:20241031T150000
DESCRIPTION:Speaker: Xiaohan Yan\nhosted by Tamas Hausel\nAbstract: The Gro
mov-Witten theory studies enumerative invariants of a projective variety $
X$ through counting nodal curves\, and gives a family of deformed multipli
cation structures on the cohomology of $X$\, known as the quantum cohomolo
gy. For flag variety $X=G/B$\, relations in its quantum cohomology may be
obtained through studying the differential equations solved by the generat
ing function known as the J-function\, which in turn come from the Toda la
ttice system of the Langlands dual group of $G$. In the first part of this
talk\, we review the story above. In the second part of this talk\, we di
scuss how much of it still holds in K-theoretic settings\, where quantum K
-theory will replace quantum cohomology\, and difference equations will re
place differential equations. Quantum K-theory arises naturally in the fra
mework of 3D mirror symmetry\, a duality between mirror holomorphic symple
ctic varieties.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Xiaohan Yan: Quantum K-theory of flag varieties
URL:https://talks-calendar.ista.ac.at/events/5351
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:66ab5b4b16fca418927948@ist.ac.at
DTSTART:20241105T153000
DTEND:20241105T163000
DESCRIPTION:Speaker: Guillaume Carlier\nhosted by Jan Maas\nAbstract: Wasse
rstein distances are known to be costly to compute in high dimensions\, th
is is why their sliced variants that only involve their one-dimensional pr
ojections have been proposed as a tractable surrogate\, indeed quite popul
ar in applications. But how reliable is really this surrogate? In this tal
k\, based on a joint work with Alessio Figalli\, Quentin Mrigot and Yi Wan
g\, I will discuss some sharp comparison results.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Guillaume Carlier: Sharp comparison between the 1-Wasserstein dista
nce and its sliced version
URL:https://talks-calendar.ista.ac.at/events/5367
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:66ab5b5c76175427746357@ist.ac.at
DTSTART:20241105T163000
DTEND:20241105T173000
DESCRIPTION:Speaker: Daniele Semola\nhosted by Jan Maas\nAbstract: Let $(M\
,g)$ be a smooth\, complete Riemannian manifold with nonnegative Ricci cur
vature\, Euclidean volume growth\, and quadratic Riemann curvature decay w
hich is not isometric to $\\mathbb{R}^n$. I will discuss joint work with G
ioacchino Antonelli and Marco Pozzetta where we prove that there exists a
set $\\mathcal{G}\\subset (0\,\\infty)$ with density one at infinity such
that for each volume $V\\in\\mathcal{G}$ there is a unique isoperimetric r
egion with volume $V$ inside $M$.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Daniele Semola: Uniqueness on average of large isoperimetric sets i
n noncompact manifolds with nonnegative Ricci curvature
URL:https://talks-calendar.ista.ac.at/events/5321
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:670cfaca1240b527965897@ist.ac.at
DTSTART:20241112T160000
DTEND:20241112T170000
DESCRIPTION:Speaker: Christa Cuchiero\nhosted by Marco Mondelli\nAbstract:
Signature methods represent a non-parametric way for extracting characteri
stic features from time series data which is essential in machine learning
tasks\, dynamic stochastic modeling\, and mathematical finance. Indeed\,
signature based approaches allow for data-driven and thus more robust mode
l selection mechanisms\, while first principles (coming e.g. from physics)
can still be guaranteed.One focus of this talk lies on the use of signatu
re as universal linear regression basis of continuous paths functionals fo
r applications in stochastic modeling. In these applications key quantitie
s that have to be computed efficiently are the expected signature or the c
haracteristic function of the signature of some underlying stochastic proc
ess. Surprisingly this can be achieved for generic classes of (jump-)diffu
sions\, called signature-SDEs (with possibly path dependent characteristic
s)\, via techniques from so-called affine and polynomial processes. More p
recisely\, we show how the signature process of these diffusions can be em
bedded in the framework of affine and polynomial processes and how the inf
inite dimensional Feynman Kac PDE can be reduced to an ODE either of Ricca
ti or linear type. In terms of concrete applications we show a portfolio s
election problem which can be reduced to a convex quadratic optimization p
roblem due to the linear structure of the signature feature set.At the end
we present some new research directions\, including novel architectures w
here signature is combined with attention mechanisms\, generative adversar
ial approaches to time series generation based on signature SDEs and neura
l signature kernel learning.The talk is based on joint works with Janka Ml
ler\, Francesca Primavera\, Sara-Svaluto Ferro and Josef Teichmann.
LOCATION:Sunstone Bldg / Ground floor / Big Seminar Room A / 27 seats (I23.
EG.102)\, ISTA
ORGANIZER:jdeanton@ist.ac.at
SUMMARY:Christa Cuchiero: (Neural)-signature methods\, applications in fina
nce and some research questions
URL:https://talks-calendar.ista.ac.at/events/5338
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:668e4d9e6b2ed870400321@ist.ac.at
DTSTART:20241112T163000
DTEND:20241112T173000
DESCRIPTION:Speaker: Oleksii Kolupaiev\nhosted by Laszlo Erdös\nAbstract:
Let $W$ be an $N\\times N$ Wigner matrix and $D$ a self-adjoint deformatio
n of the same size. It is known that for large $N$\, the resolvent $G(z)=(
W+D-z)^{-1}$ of the deformed Wigner matrix $W+D$ concentrates around its d
eterministic approximation already for $z$ just slightly above the real li
ne. This concentration phenomenon also extends to the products of multiple
resolvents\, such as $G(z_1)BG(z_2)$ for a deterministic matrix $B$. Such
results are called the multi-resolvent local laws. In our work we extend
this framework by proving the 2-resolvent local law for $G_1(z_1)BG_2(z_2)
$\, where $G_1$ and $G_2$ are resolvents of two differently deformed Wigne
r matrices $W+D_1$ and $W+D_2$. In the talk we will discuss two applicatio
ns of this result. The first one addresses the sensitivity of a quantum ev
olution to perturbations via studying the so-called Loschmidt echo\, while
the second one studies the decorrelation of eigenvectors of $W+D_1$ and $
W+D_2$. The talk is based on a joint work with G. Cipolloni\, L. Erd{\\H o
}s and J. Henheik.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Oleksii Kolupaiev: Multi-resolvent local laws for differently defor
med Wigner matrices and applications in mathematical physics
URL:https://talks-calendar.ista.ac.at/events/5380
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:648ae47517d82286496557@ist.ac.at
DTSTART:20241114T130000
DTEND:20241114T150000
DESCRIPTION:Speaker: Rachel Newton\nhosted by Tim Browning\nAbstract: Let E
and E′ be elliptic curves over Q with complex multiplication by the rin
g of integers of an imaginary quadratic field K and let Y = Kum(E×E′) b
e the minimal desingularisation of the quotient of E×E′ by the action o
f −1. We study the Brauer groups of such surfaces Y and use them to furn
ish new examples of transcendental Brauer–Manin obstructions to weak app
roximation. This is joint work with Mohamed Alaa Tawfik.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Rachel Newton: Transcendental Brauer—Manin obstructions on singul
ar K3 surfaces
URL:https://talks-calendar.ista.ac.at/events/5166
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:648ae475189a0772940927@ist.ac.at
DTSTART:20241121T130000
DTEND:20241121T150000
DESCRIPTION:Speaker: Szilard Szabo\nhosted by Tamas Hausel\nAbstract: In th
e first part\, I will explain the meaning of Hitchin WKB analysis and pres
ent some related results. In the second part\, I will explain joint work w
ith T. Mochizuki about the asymptotic behavior of large-scale solutions of
Hitchins equations that underlie the results explained in the first part.
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Szilard Szabo: Hitchin WKB analysis in higher rank
URL:https://talks-calendar.ista.ac.at/events/5167
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20241108T143419Z
UID:648ae475195b3341402767@ist.ac.at
DTSTART:20241128T130000
DTEND:20241128T150000
DESCRIPTION:Speaker: Anton Mellit\nhosted by Tamas Hausel
LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101
)\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Anton Mellit:
URL:https://talks-calendar.ista.ac.at/events/5247
END:VEVENT
END:VCALENDAR