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BEGIN:VEVENT
SUMMARY:Valdo Tatitscheff (IRMA\, Strasbourg)
DTSTART;VALUE=DATE-TIME:20220516T090000Z
DTEND;VALUE=DATE-TIME:20220516T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/2
DESCRIPTION:Title: Dimer model building via triple crossing diagrams\nby Valdo Tatitsche
ff (IRMA\, Strasbourg) as part of Séminaire de physique mathématique IPh
T\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisier
s.\n\nAbstract\nAfter having contextualized how dimer models arise in the
study of generalizations of the AdS/CFT correspondence\, I will explain ho
w triple crossing diagrams can be used to build dimer models satisfying sy
mmetry constraints and/or displaying substructures\, as well as to prove t
he non-existence of specific dimer models.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rob Klabbers (Humboldt-Universität zu Berlin)
DTSTART;VALUE=DATE-TIME:20220530T090000Z
DTEND;VALUE=DATE-TIME:20220530T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/3
DESCRIPTION:Title: Integrable PDEs\, spin chains and CFT\nby Rob Klabbers (Humboldt-Univ
ersität zu Berlin) as part of Séminaire de physique mathématique IPhT\n
\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\
n\nAbstract\nIt has been known for a long time that there are close\nconne
ctions between integrable PDEs and CFT. For example\, the\ndeep-water-wave
equation called the Benjamin-Ono (BO) equation is\nintegrable and its fir
st quantisation sits in a certain CFT. This\nconnection can be understood
by the fact that the BO equation can be\nobtained as a continuum limit of
Calogero-Sutherland (CS) models\, the\neigenfunctions of which also play a
role in the diagonalisation of the CFT.\n\nRecently a spin generalisation
of the Benjamin-Ono equation was proposed\nand named the half-wave-maps e
quation. I will discuss how this equation\nis related to CS models as well
as integrable spin chains\, thereby\nfurther entangling all these differe
nt systems and opening the door for\ninvestigations into more complex CFTs
. I will show what are the most\nnatural generalisations of this equation\
, indicating the central role\nplayed by chirality.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joonas Turunen (Laboratoire de physique\, ENS de Lyon)
DTSTART;VALUE=DATE-TIME:20220613T090000Z
DTEND;VALUE=DATE-TIME:20220613T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/4
DESCRIPTION:Title: Statistical mechanics models on random lattices of the half-plane\nby
Joonas Turunen (Laboratoire de physique\, ENS de Lyon) as part of Sémina
ire de physique mathématique IPhT\n\nLecture held in Salle Claude Itzykso
n\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nIn the main part of the t
alk\, which is mostly based on joint works with Linxiao Chen\, we start fr
om a purely combinatorial problem of random planar triangulations of the d
isk coupled with an Ising model (either on the faces or the on the vertice
s) with Dobrushin boundary conditions and at a fixed temperature. We ident
ify rigorously a phase transition by analysing the critical behaviour of t
he partition functions of a large disk at and around the critical point. M
oreover\, we study the random geometric implications of this in particular
in the local limit when the disk perimeter tends to infinity. At the crit
ical temperature\, we also find some explicit scaling limits of observable
s related to the interface lengths as well as scaling limits of perimeter
fluctuations associated with a Markovian exploration process of the half-p
lane Ising triangulation. The two key techniques in use are singularity an
alysis of rational parametrizations of generating functions\, as well as t
he aforementioned exploration process. In the remaining part (time permitt
ing)\, I will explain more informally our ongoing project with Jérémie B
outtier and Grégory Miermont about how the above approach could be genera
lized to study random planar maps of a disk decorated with O(n) loop model
s (where rational parametrizations do not necessarily exist).\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Séverin Charbonnier (IRIF\, CNRS/Université de Paris)
DTSTART;VALUE=DATE-TIME:20220620T090000Z
DTEND;VALUE=DATE-TIME:20220620T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/5
DESCRIPTION:Title: Geometric recursion on combinatorial Teichmüller space\nby Séverin
Charbonnier (IRIF\, CNRS/Université de Paris) as part of Séminaire de ph
ysique mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât.
774\, Orme des Merisiers.\n\nAbstract\nGeometric recursion is a procedure
developed in 2017 by J.E. Andersen\, G. Borot and N. Orantin\, which gene
ralizes topological recursion. For specific choices of the initial data an
d of the target theory on which the recursion runs\, it allows to recursiv
ely construct objects that capture geometric properties of surfaces that a
re useful in mathematical physics. Together with J.E. Andersen\, G. Borot\
, A. Giacchetto\, D. Lewański and C. Wheeler\, we have established a seri
es of results allowing to promote the combinatorial Teichmüller space to
a target theory for geometric recursion.\n\nI will first describe the comb
inatorial Teichmüller space and some of its properties\; second I will de
fine geometric recursion (GR) on this space. I will then give two instance
s of this recursion: the first one is akin to Mirzakhani–McShane identit
y\, the second one is a recursive formula for the count of multicurves on
combinatorial surfaces. Last\, I will expose a set of coordinates on the c
ombinatorial Teichmüller space that is well-suited for geometric recursio
n. Those coordinates allow to recover topological recursion via a procedur
e of integration: in particular for the 2 instances of the talk\, we get a
nother proof of Witten's conjecture and a recursive formula for Masur–Ve
ech volumes.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexandr Garbali (University of Melbourne)
DTSTART;VALUE=DATE-TIME:20220614T090000Z
DTEND;VALUE=DATE-TIME:20220614T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/6
DESCRIPTION:Title: Shuffle algebras and integrability\nby Alexandr Garbali (University o
f Melbourne) as part of Séminaire de physique mathématique IPhT\n\nLectu
re held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbst
ract\nI will discuss Feigin-Odesskii shuffle algebras and their connection
s with integrable models. The main example will be the trigonometric shuff
le algebra. This algebra is related to the quantum toroidal algebra of gl_
1 and is useful for studying the associated XXZ type integrable model.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea Capelli (INFN and Department of Physics\, Florence\, Italy)
DTSTART;VALUE=DATE-TIME:20220711T090000Z
DTEND;VALUE=DATE-TIME:20220711T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/7
DESCRIPTION:Title: Multipoint conformal blocks and Gaudin models\nby Andrea Capelli (INF
N and Department of Physics\, Florence\, Italy) as part of Séminaire de p
hysique mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât
. 774\, Orme des Merisiers.\n\nAbstract\nMassless fermions and anyons on t
he surface of (3+1)-dimensional topological insulators can be described at
the semiclassical level by a non-local Abelian gauge theory involving two
gauge fields. The theory is non-trivial owing to its solitonic excitatio
ns with electric and magnetic charges. We compute the partition function a
nd the solitonic spectrum\, thus showing conformal invariance and electric
-magnetic self-duality. This theory also provides a framework for semicla
ssical bosonization of (2+1)d fermions.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Erik Tonni (SISSA)
DTSTART;VALUE=DATE-TIME:20220718T090000Z
DTEND;VALUE=DATE-TIME:20220718T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/8
DESCRIPTION:Title: Entanglement entropies for Lifshitz fermionic fields at finite density\nby Erik Tonni (SISSA) as part of Séminaire de physique mathématique I
PhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisi
ers.\n\nAbstract\nThe entanglement entropies of an interval for the free f
ermionic spinless Schroedinger field theory at finite density and zero tem
perature are investigated. The interval is either on the line or at the be
ginning of the half line\, when either Neumann or Dirichlet boundary condi
tions are imposed at the origin. We show that the entanglement entropies a
re finite functions of a dimensionless parameter proportional to the area
of the rectangular region in the phase space identified by the Fermi momen
tum and the length of the interval. \nFor the interval on the line\, the e
ntanglement entropy is a monotonically increasing function. Instead\, for
the interval on the half line\, it displays an oscillatory behaviour relat
ed to the Friedel oscillations of the mean particle density at the entangl
ing point. \nBy employing the properties of the prolate spheroidal wave fu
nctions or the expansions of the tau functions of the kernels occurring in
the spectral problems\, determined by the two point function\, we find an
alytic expressions for the expansions of the entanglement entropies in the
asymptotic regimes of small and large area of the rectangular phase space
region. Extending our analysis to a class of free fermionic Lifshitz mode
ls\, we find that the parity of the Lifshitz exponent determines the prope
rties of the bipartite entanglement.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kirone Mallick (IPhT)
DTSTART;VALUE=DATE-TIME:20221010T090000Z
DTEND;VALUE=DATE-TIME:20221010T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/9
DESCRIPTION:Title: An exact solution of the macroscopic fluctuation theory\nby Kirone Ma
llick (IPhT) as part of Séminaire de physique mathématique IPhT\n\nLectu
re held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbst
ract\nInteracting diffusive particle systems are paradigms for\nnon-equil
ibrium statistical physics. Their macroscopic behaviour follows\na variati
onal principle\, proposed by G. Jona-Lasinio and his collaborators\,\nknow
n as the Macroscopic Fluctuation Theory (MFT)\, in which physics\nout from
equilibrium is determined at a coarse-grained scale by two\ncoupled non-l
inear hydrodynamic equations.\n\nIn this talk\, we shall show that the MFT
equations for the exclusion process \nare classically integrable\, i.e. t
hey can be integrated by \ninverse scattering\, a method originally used
to study solitons in the KdV or\nthe NLS equations. Our exact solution wi
ll allow us to understand how large\ndeviations are generated by atypica
l fluctuations\, far from equilibrium.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sofia Tarricone (Institut de Physique Théorique\, CEA Paris-Sacla
y)
DTSTART;VALUE=DATE-TIME:20221114T100000Z
DTEND;VALUE=DATE-TIME:20221114T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/10
DESCRIPTION:Title: On the integrability of the Airy kernel and beyond\nby Sofia Tarrico
ne (Institut de Physique Théorique\, CEA Paris-Saclay) as part of Sémina
ire de physique mathématique IPhT\n\nLecture held in Salle Claude Itzykso
n\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nThe aim of this talk is t
o describe the various integrable probability models and integrable system
s related to the Airy kernel and some of its recent generalizations that I
worked on during the last years. In particular\, we will focus on the pro
perties of Fredholm determinants of the so-called finite temperature Airy
kernel and its higher order analogues (based on a joint work with T. Bothn
er and M. Cafasso) and on the properties of a finite rank deformation of t
he same (based on ongoing work with T. Claeys\, G. Glesner and G. Ruzza).\
n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fedor Levkovich-Maslyuk
DTSTART;VALUE=DATE-TIME:20221121T100000Z
DTEND;VALUE=DATE-TIME:20221121T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/11
DESCRIPTION:Title: Separation of variables and correlation functions\nby Fedor Levkovic
h-Maslyuk as part of Séminaire de physique mathématique IPhT\n\nLecture
held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstrac
t\nI will present new results in the separation of variables (SoV) program
for integrable models. The SoV methods are expected to be very powerful b
ut until recently have been barely developed beyond the simplest gl(2) exa
mples. I will describe how to realize the SoV for any gl(N) spin chain and
demonstrate how to solve the longstanding problem of deriving the scalar
product measure in SoV. Using these results I will show how to compute a l
arge class of correlation functions and overlaps in a compact determinant
form. I will also demonstrate the power of SoV in 4d integrable CFT's such
as the 'fishnet' theory and outline highly promising applications in comp
utation of exact correlators in N=4 super Yang-Mills theory.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Philippe Biane (Institut Gaspard Monge\, CNRS et Université Paris
-Est)
DTSTART;VALUE=DATE-TIME:20221128T100000Z
DTEND;VALUE=DATE-TIME:20221128T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/12
DESCRIPTION:Title: Processus d'exclusion simple quantique et cumulants libres\nby Phili
ppe Biane (Institut Gaspard Monge\, CNRS et Université Paris-Est) as part
of Séminaire de physique mathématique IPhT\n\nLecture held in Salle Cla
ude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nJe montrerai c
omment les fluctuations du processus d'exclusion simple quantique (une ver
sion quantique du fameux processus d'exclusion\, qui a été introduite r
écemment dans la littérature physique) peuvent être décrites au moyen
de cumulants libres\, des quantités qui apparaissent dans un tout autre d
omaine: les probabilités libres et les matrices aléatoires.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carlos Bercini (DESY)
DTSTART;VALUE=DATE-TIME:20221219T100000Z
DTEND;VALUE=DATE-TIME:20221219T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/13
DESCRIPTION:Title: Structure Constants in N = 4 SYM and Separation of Variables\nby Car
los Bercini (DESY) as part of Séminaire de physique mathématique IPhT\n\
nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n
\nAbstract\nWe propose a new framework for computing three-point functions
in planar N = 4 super Yang Mills where these correlators take the form of
multiple integrals of Separation of Variables type. We test this formalis
m at weak coupling at leading and next-to-leading orders in a non-compact
SL(2) sector of the theory and all the way to next-to-next-to-leading orde
rs for a compact SU(2) sector.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrew Elvey Price (Institut Denis Poisson\, CNRS et Université d
e Tours)
DTSTART;VALUE=DATE-TIME:20230109T100000Z
DTEND;VALUE=DATE-TIME:20230109T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/14
DESCRIPTION:Title: Enumeration of walks by winding angle\nby Andrew Elvey Price (Instit
ut Denis Poisson\, CNRS et Université de Tours) as part of Séminaire de
physique mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bâ
t. 774\, Orme des Merisiers.\n\nAbstract\nHow much does a random walk wind
around a given point? At the large scale this question has been well unde
rstood since the 80's thanks to work by Spitzer\, Belisle\, Rudnick\, Hu a
nd many others. In 2017\, Budd gave the first exact results for this probl
em\, by solving it on the square lattice. In this talk I will describe my
exact solutions for a more general class of models\, namely walks with sma
ll steps.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Éric Vernier (LPSM\, CNRS et Sorbonne Université)
DTSTART;VALUE=DATE-TIME:20230123T100000Z
DTEND;VALUE=DATE-TIME:20230123T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/15
DESCRIPTION:Title: Onsager algebra and Ising-type structures in root-of-unity six-vertex mo
dels\nby Éric Vernier (LPSM\, CNRS et Sorbonne Université) as part o
f Séminaire de physique mathématique IPhT\n\nLecture held in Salle Claud
e Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nI will start by
reviewing a surprising connection between the six vertex model (or its hig
her spin generalizations) and the Onsager algebra\, an infinite-dimensiona
l Lie algebra which appeared in the solution of the two-dimensional Ising
model. Using Kramers-Wannier duality\, a family of N-states integrable ver
tex models/quantum spin chains are constructed having the Onsager algebra
as a symmetry algebra. Those are then identified as the six-vertex model a
nd its higher-spin descendents\, at specific "root-of-unity" values of the
anisotropy parameter. While the integrability of six-vertex models is fam
ously related to an underlying quantum group structure\, the enlarged Onsa
ger symmetry could similarly be related to exotic quantum group representa
tions occuring at root of unity. However\, this leaves certain aspects suc
h as duality somewhat hidden in the six-vertex/quantum group formulation.
I will therefore revert the logic and show that the (higher spin) root-of-
unity six-vertex models can be re-expressed more simply in terms of Ising
(clock) spins with products of 2-spins interactions only. The Onsager alge
bra symmetry emerges naturally in this framework\, and the quantum-group r
elated structures and Yang-Baxter equations of the vertex models can be tr
aced back to simpler star-triangle equations in the spin formulation. This
is based on E. Vernier\, E. O'Brien\, P. Fendley\, JSTAT (2019)\, and som
e work in preparation.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emmanuel Guitter (IPhT)
DTSTART;VALUE=DATE-TIME:20230213T100000Z
DTEND;VALUE=DATE-TIME:20230213T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/16
DESCRIPTION:Title: Hamiltonian paths on random bicubic maps and KPZ\nby Emmanuel Guitte
r (IPhT) as part of Séminaire de physique mathématique IPhT\n\nLecture h
eld in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract
\nThe enumeration of Hamiltonian paths on random bicubic maps is a very si
mply stated combinatorial problem that still awaits an exact solution. In
this talk\, I will present estimates of configuration exponents for the as
ymptotics of ensembles of such Hamiltonian paths with possible defects\, a
s obtained from extrapolations of exact enumerations for finite sizes. I w
ill then compare these measured exponents with theoretical predictions bas
ed on the Knizhnik\, Polyakov\, Zamolodchikov (KPZ) relations applied to c
lassical dimensions for fully packed loops on the honeycomb lattice. I wil
l show that a naive use of the KPZ relations does not reproduce the measur
ed exponents but that a simple modification of a parameter in their applic
ation can eventually correct the observed discrepancy. I will also show th
at a similar modification is needed to reproduce via the KPZ formulas some
exactly known exponents for the closely related problem of fully packed u
nweighted loops on random planar bicubic maps. \nThis presentation is base
d on joint work with Philippe Di Francesco\, Bertrand Duplantier and Olivi
er Golinelli.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jules Lamers (IPhT)
DTSTART;VALUE=DATE-TIME:20230320T100000Z
DTEND;VALUE=DATE-TIME:20230320T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/19
DESCRIPTION:Title: The partially (an)isotropic Inozemtsev spin chain\nby Jules Lamers (
IPhT) as part of Séminaire de physique mathématique IPhT\n\nLecture held
in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nT
raditionally\, (quantum) integrable spin chains are studied under the assu
mption of short-range interactions between the spins\, leading to the near
est-neighbour Heisenberg chains. The most famous integrable model with lon
g-range spin interactions is the Haldane--Shastry chain\, whose integrable
structure was uncovered at IPhT about thirty years ago. The Inozemtsev sp
in chain\, which famously made a guest appearance in AdS/CFT integrability
\, interpolates between the Heisenberg XXX and Haldane--Shastry chains whi
le being exactly solvable throughout. Although widely believe to be integr
able\, the algebraic structure underlying the Inozemtsev chain is not yet
known.\n\nOne way to learn about something is to try and deform it. For sp
in chains\, it is natural to try and break the SU(2) spin symmetry ('isotr
opy') down to spin-z symmetry ('partial (an)isotropy') in a way that prese
rves the key features. In my talk I will present a new long-range spin cha
in: the partially (an)isotropic Inozemtsev chain. It is integrable in that
it has a hierarchy of commuting hamiltonians. In the long-range limit it
becomes the (known) partially (an)isotropic generalisation of Haldane--Sha
stry\, while in the short-range limit it gives a variant of Heisenberg XXZ
with nontrivial boundary conditions. Underlying the model is a new quantu
m many-body system with spins that generalises the elliptic Ruijsenaars mo
del.\n\nBased on work in progress with Rob Klabbers (Humboldt U Berlin)\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sylvie Corteel (IRIF\, CNRS et Université Paris Cité)
DTSTART;VALUE=DATE-TIME:20230327T090000Z
DTEND;VALUE=DATE-TIME:20230327T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/20
DESCRIPTION:Title: Pavage par dominos et suites de partitions\nby Sylvie Corteel (IRIF\
, CNRS et Université Paris Cité) as part of Séminaire de physique math
ématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme
des Merisiers.\n\nAbstract\nJ'expliquerai le lien entre pavages par domin
os et suites de partitions\, une idée développée entre autres en collab
oration avec Jérémie Bouttier. Je montrerai comment on peut rajouter une
condition "symplectique" sur ces suites de partitions et définirai les p
avages du triangle Aztec généralisé. Pour certaines formes on retrouve
le triangle Aztec défini par Philippe Di Francesco. Dans certains cas on
montre que le nombre de pavages a une jolie formule produit. Travail en co
llaboration avec Freddie Huang et Christian Krattenthaler. [The talk was g
iven in English.]\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Valentin Féray (IECL\, CNRS et Université de Lorraine)
DTSTART;VALUE=DATE-TIME:20230403T090000Z
DTEND;VALUE=DATE-TIME:20230403T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/21
DESCRIPTION:Title: Components of meandric systems and the infinite noodle\nby Valentin
Féray (IECL\, CNRS et Université de Lorraine) as part of Séminaire de p
hysique mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât
. 774\, Orme des Merisiers.\n\nAbstract\nA meandric system of size n is a
non-intersecting collection of closed loops in the plane crossing the real
line in exactly 2n points (up to continuous deformation). In mathematical
physics terms\, it can be seen as a loop model on a random lattice. Conne
cted meandric systems are called meanders\, and their enumeration is a not
orious hard problem in enumerative combinatorics. In this talk\, we discus
s a different question\, raised independently by Goulden--Nica--Puder and
Kargin: what is the number of connected components $cc(M_n)$ of a uniform
random meandric system of size 2n? We prove that this number grows linear
with n\, and concentrates around its mean value\, in the sense that $cc(M_
n)/n$ converges in probability to a constant. Our main tool is the definit
ion of a notion of local convergence for meandric systems\, and the identi
fication of the “quenched Benjamini--Schramm” limit of $M_n$. The latt
er is the so-called infinite noodle\, a largely not understood percolation
model recently introduced by Curien\, Kozma\, Sidoravicius and Tournier.
\n\nOur main result has also a geometric interpretation\, regarding the Ha
sse diagram $H_n$ of the non-crossing partition lattice $NC(n)$: informall
y\, our result implies that\, in $H_n$\, almost all pairs of vertices are
asymptotically at the same distance from each other. We use here a connect
ion between $H_n$ and meandric systems discovered by Goulden\, Nica and Pu
der. \n\nBased on joint work with Paul Thevenin (University of Vienna).\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lauren Williams (Harvard University)
DTSTART;VALUE=DATE-TIME:20230515T090000Z
DTEND;VALUE=DATE-TIME:20230515T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/22
DESCRIPTION:Title: The positive Grassmannian\, the amplituhedron\, and cluster algebras
\nby Lauren Williams (Harvard University) as part of Séminaire de physiqu
e mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\
, Orme des Merisiers.\n\nAbstract\nI will give a gentle introduction to th
e positive Grassmannian and the amplituhedron\, a geometric object that wa
s introduced in the context of scattering amplitudes in N=4 super Yang Mil
ls. I'll then explain some of the connections of the amplituhedron to com
binatorics and to cluster algebras.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sylvain Ribault (IPhT)
DTSTART;VALUE=DATE-TIME:20230206T100000Z
DTEND;VALUE=DATE-TIME:20230206T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/23
DESCRIPTION:Title: From combinatorial maps to correlation functions in loop models\nby
Sylvain Ribault (IPhT) as part of Séminaire de physique mathématique IPh
T\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisier
s.\n\nAbstract\nIn the two-dimensional O(n) and Potts models\, some observ
ables can be computed as weighted sums over configurations of non-intersec
ting loops.\n\nI will define weighted sums associated to a large class of
combinatorial maps\, also known as ribbon graphs\, fatgraphs or rotation s
ystems. Given a map with $N$ vertices\, this yields a function of the modu
li of the corresponding punctured Riemann surface\, which I will call an $
N$-point correlation function.\n\nI will conjecture that in the critical l
imit\, such correlation functions form a basis of solutions of certain con
formal bootstrap equations. They include all correlation functions of the
O(n) and Potts models\, and correlation functions that do not belong to an
y known model.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jeanne Scott (Brandeis University)
DTSTART;VALUE=DATE-TIME:20230306T100000Z
DTEND;VALUE=DATE-TIME:20230306T110000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/24
DESCRIPTION:Title: Clone symmetric function theory\nby Jeanne Scott (Brandeis Universit
y) as part of Séminaire de physique mathématique IPhT\n\nLecture held in
Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nIn 1
994 S. Okada introduced a family of non-commutative polynomials satisfying
a Pieri-type identity which recapitulates the branching rule of R. Stanle
y's Young-Fibonacci lattice. More generally\, products of these so called
"clone" Schur functions were shown to obey a non-commutative version of th
e Littlewood-Richardson identity with structure constants determined combi
natorially from the Young-Fibonacci lattice structure. \n\nIn this talk I'
ll survey Okada's clone theory with the aim of drawing parallels with the
(classical) theory of symmetric functions\, the representation theory of t
he symmetric group\, and the combinatorics of the Young lattice. I'd also
like to use the opportunity to report on some speculative work based on di
scussions with Leonid Petrov: Specifically a new concept of total positivi
ty related to clone Schur functions together with a corresponding "Stieltj
es" moment problem. If there's time\, I'll pose an open problem to the aud
ience of whether a matrix model can be meaningfully associated to certain
clone "tau" functions.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Laurent Chevillard (Laboratoire de physique\, CNRS et ENS de Lyon)
DTSTART;VALUE=DATE-TIME:20230605T090000Z
DTEND;VALUE=DATE-TIME:20230605T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/25
DESCRIPTION:Title: The phenomenology of fluid turbulence\, and its stochastic representatio
n\nby Laurent Chevillard (Laboratoire de physique\, CNRS et ENS de Lyo
n) as part of Séminaire de physique mathématique IPhT\n\nLecture held in
Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nI wi
ll begin with presenting and illustrating the standard phenomenology of th
ree-dimensional (statistically) isotropic and homogeneous fluid turbulence
\, which is mainly attributed to Kolmogorov. Then\, while designing random
fields able to reproduce/model the implied intricate spatial structure of
kinematic quantities of interest\, and some crucial mechanisms of the Nav
ier-Stokes equations\, I will explain how come the celebrated Harish-Chand
ra--Itzykson--Zuber integral over the orthogonal group enters in a probabi
listic picture of such a phenomenology. This aspect has been developed wit
h C. Garban\, R. Pereira\, R. Rhodes\, R. Robert and V. Vargas.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jean-Baptiste Fouvry (CNRS\, Institut d'Astrophysique de Paris)
DTSTART;VALUE=DATE-TIME:20230612T090000Z
DTEND;VALUE=DATE-TIME:20230612T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/26
DESCRIPTION:Title: Stellar Dynamics in Galactic Nuclei\nby Jean-Baptiste Fouvry (CNRS\,
Institut d'Astrophysique de Paris) as part of Séminaire de physique math
ématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme
des Merisiers.\n\nAbstract\nMost galaxies harbor a supermassive black hol
e in their centre around which orbits a stellar cluster\, the galactic nuc
leus. The unique proximity of the Milky-Way's central black hole\, SgrA*\,
offers an extraordinary opportunity to study such a crowded environment.
Although galactic nuclei are among the densest stellar systems in the univ
erse\, the steep potential well generated by the central black hole allows
for efficient long-term orbit-averaged interactions between the stars.\n\
nUltimately\, this drives the relaxation of the stellar orbits through an
intricate hierarchy of dynamical processes. In this presentation\, I will
report on recent developments in kinetic theory\, describe efficient numer
ical methods to simulate these dynamics\, and present first quantitative a
pplications of these frameworks to constrain SgrA*'s stellar content.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gilles Parez (Université de Montréal)
DTSTART;VALUE=DATE-TIME:20230522T120000Z
DTEND;VALUE=DATE-TIME:20230522T130000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/27
DESCRIPTION:Title: Entanglement and separability of Rokhsar-Kivelson and resonating valence
-bond states\nby Gilles Parez (Université de Montréal) as part of S
éminaire de physique mathématique IPhT\n\nLecture held in Salle Claude I
tzykson\, Bât. 774\, Orme des Merisiers.\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Guillaume Baverez (Humboldt-Universität zu Berlin)
DTSTART;VALUE=DATE-TIME:20230619T120000Z
DTEND;VALUE=DATE-TIME:20230619T130000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/28
DESCRIPTION:Title: Liouville theory: from Segal's axioms to conformal blocks\nby Guilla
ume Baverez (Humboldt-Universität zu Berlin) as part of Séminaire de phy
sique mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât.
774\, Orme des Merisiers.\n\nAbstract\nIn Segal's axiomatisation\, conform
al field theories (CFT) can be constructed from (projective) representatio
ns of the semigroup of annuli (the set of annuli with parametrised boundar
ies endowed with the gluing operation). In the case of the Liouville CFT\,
we realise this idea by defining a certain family of Markov processes on
the space of distributions on the unit circle. Their generators exist as u
nbounded operators on the Hilbert space and represent the Virasoro algebra
(they are equivalent to the Sugawara construction). \nThis representation
is instrumental in the study of the conformal blocks of the theory. We ca
n define them using pants decomposition of the underlying surface\, and as
sociate an operator in the Hilbert space to each pair of pants. The gluing
of pairs of pants is represented by the composition of operators\, and th
e conformal blocks are essentially the spectral decomposition of these ope
rators. Their variation with respect to the complex structure of the surfa
ce is governed by the semigroup\, which is a version of the statement that
conformal blocks are horizontal with respect to the connection defined by
the stress-energy tensor. This allows us to show that the blocks do not d
epend on the choice of curves representing the pants decomposition. \nBase
d on joint and ongoing works with Guillarmou\, Kupiainen\, Rhodes & Vargas
.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jens Hoppe (Technische Universität Braunschweig)
DTSTART;VALUE=DATE-TIME:20230626T090000Z
DTEND;VALUE=DATE-TIME:20230626T100000Z
DTSTAMP;VALUE=DATE-TIME:20240804T050730Z
UID:IPHT-PHM/29
DESCRIPTION:Title: Recent progress in Membrane Theory\, and reduced Yang Mills\nby Jens
Hoppe (Technische Universität Braunschweig) as part of Séminaire de phy
sique mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât.
774\, Orme des Merisiers.\n\nAbstract\nExplicit solutions\, and Baecklund
transformations relating them\,\nwill be presented\, as well as an Ansatz
for the simplest SU(2) matrix model.\n
LOCATION:https://researchseminars.org/talk/IPHT-PHM/29/
END:VEVENT
END:VCALENDAR