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BEGIN:VEVENT
SUMMARY:Valdo Tatitscheff (IRMA\, Strasbourg)
DTSTART:20220516T090000Z
DTEND:20220516T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/2
DESCRIPTION:Title: Dimer model building via triple crossing diagrams\nby Valdo Ta
titscheff (IRMA\, Strasbourg) as part of Séminaire de physique mathémati
que IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des M
erisiers.\n\nAbstract\nAfter having contextualized how dimer models arise
in the study of generalizations of the AdS/CFT correspondence\, I will exp
lain how triple crossing diagrams can be used to build dimer models satisf
ying symmetry constraints and/or displaying substructures\, as well as to
prove the non-existence of specific dimer models.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rob Klabbers (Humboldt-Universität zu Berlin)
DTSTART:20220530T090000Z
DTEND:20220530T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/3
DESCRIPTION:Title: Integrable PDEs\, spin chains and CFT\nby Rob Klabbers (Humbol
dt-Universität zu Berlin) as part of Séminaire de physique mathématique
IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Meri
siers.\n\nAbstract\nIt has been known for a long time that there are close
\nconnections between integrable PDEs and CFT. For example\, the\ndeep-wat
er-wave equation called the Benjamin-Ono (BO) equation is\nintegrable and
its first quantisation sits in a certain CFT. This\nconnection can be unde
rstood by the fact that the BO equation can be\nobtained as a continuum li
mit of Calogero-Sutherland (CS) models\, the\neigenfunctions of which also
play a role in the diagonalisation of the CFT.\n\nRecently a spin general
isation of the Benjamin-Ono equation was proposed\nand named the half-wave
-maps equation. I will discuss how this equation\nis related to CS models
as well as integrable spin chains\, thereby\nfurther entangling all these
different systems and opening the door for\ninvestigations into more compl
ex CFTs. I will show what are the most\nnatural generalisations of this eq
uation\, indicating the central role\nplayed by chirality.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joonas Turunen (Laboratoire de physique\, ENS de Lyon)
DTSTART:20220613T090000Z
DTEND:20220613T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/4
DESCRIPTION:Title: Statistical mechanics models on random lattices of the half-plane<
/a>\nby Joonas Turunen (Laboratoire de physique\, ENS de Lyon) as part of
Séminaire de physique mathématique IPhT\n\nLecture held in Salle Claude
Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nIn the main part o
f the talk\, which is mostly based on joint works with Linxiao Chen\, we s
tart from a purely combinatorial problem of random planar triangulations o
f the disk coupled with an Ising model (either on the faces or the on the
vertices) with Dobrushin boundary conditions and at a fixed temperature. W
e identify rigorously a phase transition by analysing the critical behavio
ur of the partition functions of a large disk at and around the critical p
oint. Moreover\, we study the random geometric implications of this in par
ticular in the local limit when the disk perimeter tends to infinity. At t
he critical temperature\, we also find some explicit scaling limits of obs
ervables related to the interface lengths as well as scaling limits of per
imeter fluctuations associated with a Markovian exploration process of the
half-plane Ising triangulation. The two key techniques in use are singula
rity analysis of rational parametrizations of generating functions\, as we
ll as the aforementioned exploration process. In the remaining part (time
permitting)\, I will explain more informally our ongoing project with Jér
émie Bouttier and Grégory Miermont about how the above approach could be
generalized to study random planar maps of a disk decorated with O(n) loo
p models (where rational parametrizations do not necessarily exist).\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Séverin Charbonnier (IRIF\, CNRS/Université de Paris)
DTSTART:20220620T090000Z
DTEND:20220620T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/5
DESCRIPTION:Title: Geometric recursion on combinatorial Teichmüller space\nby S
éverin Charbonnier (IRIF\, CNRS/Université de Paris) as part of Séminai
re de physique mathématique IPhT\n\nLecture held in Salle Claude Itzykson
\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nGeometric recursion is a p
rocedure developed in 2017 by J.E. Andersen\, G. Borot and N. Orantin\, wh
ich generalizes topological recursion. For specific choices of the initial
data and of the target theory on which the recursion runs\, it allows to
recursively construct objects that capture geometric properties of surface
s that are useful in mathematical physics. Together with J.E. Andersen\, G
. Borot\, A. Giacchetto\, D. Lewański and C. Wheeler\, we have establishe
d a series of results allowing to promote the combinatorial Teichmüller s
pace to a target theory for geometric recursion.\n\nI will first describe
the combinatorial Teichmüller space and some of its properties\; second I
will define geometric recursion (GR) on this space. I will then give two
instances of this recursion: the first one is akin to Mirzakhani–McShane
identity\, the second one is a recursive formula for the count of multicu
rves on combinatorial surfaces. Last\, I will expose a set of coordinates
on the combinatorial Teichmüller space that is well-suited for geometric
recursion. Those coordinates allow to recover topological recursion via a
procedure of integration: in particular for the 2 instances of the talk\,
we get another proof of Witten's conjecture and a recursive formula for Ma
sur–Veech volumes.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexandr Garbali (University of Melbourne)
DTSTART:20220614T090000Z
DTEND:20220614T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/6
DESCRIPTION:Title: Shuffle algebras and integrability\nby Alexandr Garbali (Unive
rsity of Melbourne) as part of Séminaire de physique mathématique IPhT\n
\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\
n\nAbstract\nI will discuss Feigin-Odesskii shuffle algebras and their con
nections with integrable models. The main example will be the trigonometri
c shuffle algebra. This algebra is related to the quantum toroidal algebra
of gl_1 and is useful for studying the associated XXZ type integrable mod
el.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea Capelli (INFN and Department of Physics\, Florence\, Italy)
DTSTART:20220711T090000Z
DTEND:20220711T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/7
DESCRIPTION:Title: Multipoint conformal blocks and Gaudin models\nby Andrea Capel
li (INFN and Department of Physics\, Florence\, Italy) as part of Séminai
re de physique mathématique IPhT\n\nLecture held in Salle Claude Itzykson
\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nMassless fermions and anyo
ns on the surface of (3+1)-dimensional topological insulators can be descr
ibed at the semiclassical level by a non-local Abelian gauge theory involv
ing two gauge fields. The theory is non-trivial owing to its solitonic ex
citations with electric and magnetic charges. We compute the partition fun
ction and the solitonic spectrum\, thus showing conformal invariance and e
lectric-magnetic self-duality. This theory also provides a framework for
semiclassical bosonization of (2+1)d fermions.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Erik Tonni (SISSA)
DTSTART:20220718T090000Z
DTEND:20220718T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/8
DESCRIPTION:Title: Entanglement entropies for Lifshitz fermionic fields at finite den
sity\nby Erik Tonni (SISSA) as part of Séminaire de physique mathéma
tique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des
Merisiers.\n\nAbstract\nThe entanglement entropies of an interval for the
free fermionic spinless Schroedinger field theory at finite density and z
ero temperature are investigated. The interval is either on the line or at
the beginning of the half line\, when either Neumann or Dirichlet boundar
y conditions are imposed at the origin. We show that the entanglement entr
opies are finite functions of a dimensionless parameter proportional to th
e area of the rectangular region in the phase space identified by the Ferm
i momentum and the length of the interval. \nFor the interval on the line\
, the entanglement entropy is a monotonically increasing function. Instead
\, for the interval on the half line\, it displays an oscillatory behaviou
r related to the Friedel oscillations of the mean particle density at the
entangling point. \nBy employing the properties of the prolate spheroidal
wave functions or the expansions of the tau functions of the kernels occur
ring in the spectral problems\, determined by the two point function\, we
find analytic expressions for the expansions of the entanglement entropies
in the asymptotic regimes of small and large area of the rectangular phas
e space region. Extending our analysis to a class of free fermionic Lifshi
tz models\, we find that the parity of the Lifshitz exponent determines th
e properties of the bipartite entanglement.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kirone Mallick (IPhT)
DTSTART:20221010T090000Z
DTEND:20221010T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/9
DESCRIPTION:Title: An exact solution of the macroscopic fluctuation theory\nby Ki
rone Mallick (IPhT) as part of Séminaire de physique mathématique IPhT\n
\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\
n\nAbstract\nInteracting diffusive particle systems are paradigms for\nno
n-equilibrium statistical physics. Their macroscopic behaviour follows\na
variational principle\, proposed by G. Jona-Lasinio and his collaborators\
,\nknown as the Macroscopic Fluctuation Theory (MFT)\, in which physics\no
ut from equilibrium is determined at a coarse-grained scale by two\ncouple
d non-linear hydrodynamic equations.\n\nIn this talk\, we shall show that
the MFT equations for the exclusion process \nare classically integrable\,
i.e. they can be integrated by \ninverse scattering\, a method originall
y used to study solitons in the KdV or\nthe NLS equations. Our exact solu
tion will allow us to understand how large\ndeviations are generated by
atypical fluctuations\, far from equilibrium.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sofia Tarricone (Institut de Physique Théorique\, CEA Paris-Sacla
y)
DTSTART:20221114T100000Z
DTEND:20221114T110000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/10
DESCRIPTION:Title: On the integrability of the Airy kernel and beyond\nby Sofia
Tarricone (Institut de Physique Théorique\, CEA Paris-Saclay) as part of
Séminaire de physique mathématique IPhT\n\nLecture held in Salle Claude
Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nThe aim of this ta
lk is to describe the various integrable probability models and integrable
systems 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 properties of Fredholm determinants of the so-called finite temperatur
e Airy kernel and its higher order analogues (based on a joint work with T
. Bothner and M. Cafasso) and on the properties of a finite rank deformati
on of the same (based on ongoing work with T. Claeys\, G. Glesner and G. R
uzza).\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fedor Levkovich-Maslyuk
DTSTART:20221121T100000Z
DTEND:20221121T110000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/11
DESCRIPTION:Title: Separation of variables and correlation functions\nby Fedor L
evkovich-Maslyuk as part of Séminaire de physique mathématique IPhT\n\nL
ecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\n
Abstract\nI will present new results in the separation of variables (SoV)
program for integrable models. The SoV methods are expected to be very pow
erful but until recently have been barely developed beyond the simplest gl
(2) examples. I will describe how to realize the SoV for any gl(N) spin ch
ain and demonstrate how to solve the longstanding problem of deriving the
scalar product measure in SoV. Using these results I will show how to comp
ute a large class of correlation functions and overlaps in a compact deter
minant 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 computation of exact correlators in N=4 super Yang-Mills theory.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Philippe Biane (Institut Gaspard Monge\, CNRS et Université Paris
-Est)
DTSTART:20221128T100000Z
DTEND:20221128T110000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/12
DESCRIPTION:Title: Processus d'exclusion simple quantique et cumulants libres\nb
y Philippe Biane (Institut Gaspard Monge\, CNRS et Université Paris-Est)
as part of Séminaire de physique mathématique IPhT\n\nLecture held in Sa
lle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nJe mont
rerai comment les fluctuations du processus d'exclusion simple quantique (
une version quantique du fameux processus d'exclusion\, qui a été introd
uite récemment dans la littérature physique) peuvent être décrites au
moyen de cumulants libres\, des quantités qui apparaissent dans un tout a
utre domaine: les probabilités libres et les matrices aléatoires.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carlos Bercini (DESY)
DTSTART:20221219T100000Z
DTEND:20221219T110000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/13
DESCRIPTION:Title: Structure Constants in N = 4 SYM and Separation of Variables\
nby Carlos Bercini (DESY) as part of Séminaire de physique mathématique
IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des Meris
iers.\n\nAbstract\nWe propose a new framework for computing three-point fu
nctions in planar N = 4 super Yang Mills where these correlators take the
form of multiple integrals of Separation of Variables type. We test this f
ormalism at weak coupling at leading and next-to-leading orders in a non-c
ompact SL(2) sector of the theory and all the way to next-to-next-to-leadi
ng orders for a compact SU(2) sector.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrew Elvey Price (Institut Denis Poisson\, CNRS et Université d
e Tours)
DTSTART:20230109T100000Z
DTEND:20230109T110000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/14
DESCRIPTION:Title: Enumeration of walks by winding angle\nby Andrew Elvey Price
(Institut Denis Poisson\, CNRS et Université de Tours) as part of Sémina
ire de physique mathématique IPhT\n\nLecture held in Salle Claude Itzykso
n\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nHow much does a random wa
lk wind around a given point? At the large scale this question has been we
ll understood since the 80's thanks to work by Spitzer\, Belisle\, Rudnick
\, Hu and many others. In 2017\, Budd gave the first exact results for thi
s problem\, by solving it on the square lattice. In this talk I will descr
ibe my exact solutions for a more general class of models\, namely walks w
ith small steps.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Éric Vernier (LPSM\, CNRS et Sorbonne Université)
DTSTART:20230123T100000Z
DTEND:20230123T110000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/15
DESCRIPTION:Title: Onsager algebra and Ising-type structures in root-of-unity six-ve
rtex models\nby Éric Vernier (LPSM\, CNRS et Sorbonne Université) as
part of Séminaire de physique mathématique IPhT\n\nLecture held in Sall
e Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstract\nI will st
art by reviewing a surprising connection between the six vertex model (or
its higher spin generalizations) and the Onsager algebra\, an infinite-dim
ensional Lie algebra which appeared in the solution of the two-dimensional
Ising model. Using Kramers-Wannier duality\, a family of N-states integra
ble vertex models/quantum spin chains are constructed having the Onsager a
lgebra as a symmetry algebra. Those are then identified as the six-vertex
model and its higher-spin descendents\, at specific "root-of-unity" values
of the anisotropy parameter. While the integrability of six-vertex models
is famously related to an underlying quantum group structure\, the enlarg
ed Onsager symmetry could similarly be related to exotic quantum group rep
resentations occuring at root of unity. However\, this leaves certain aspe
cts such as duality somewhat hidden in the six-vertex/quantum group formul
ation. I will therefore revert the logic and show that the (higher spin) r
oot-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 Onsag
er algebra symmetry emerges naturally in this framework\, and the quantum-
group related structures and Yang-Baxter equations of the vertex models ca
n be traced back to simpler star-triangle equations in the spin formulatio
n. This is based on E. Vernier\, E. O'Brien\, P. Fendley\, JSTAT (2019)\,
and some work in preparation.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emmanuel Guitter (IPhT)
DTSTART:20230213T100000Z
DTEND:20230213T110000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/16
DESCRIPTION:Title: Hamiltonian paths on random bicubic maps and KPZ\nby Emmanuel
Guitter (IPhT) as part of Séminaire de physique mathématique IPhT\n\nLe
cture held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nA
bstract\nThe enumeration of Hamiltonian paths on random bicubic maps is a
very simply stated combinatorial problem that still awaits an exact soluti
on. In this talk\, I will present estimates of configuration exponents for
the asymptotics of ensembles of such Hamiltonian paths with possible defe
cts\, as obtained from extrapolations of exact enumerations for finite siz
es. I will then compare these measured exponents with theoretical predicti
ons based on the Knizhnik\, Polyakov\, Zamolodchikov (KPZ) relations appli
ed to classical dimensions for fully packed loops on the honeycomb lattice
. I will show that a naive use of the KPZ relations does not reproduce the
measured exponents but that a simple modification of a parameter in their
application can eventually correct the observed discrepancy. I will also
show that a similar modification is needed to reproduce via the KPZ formul
as some exactly known exponents for the closely related problem of fully p
acked unweighted loops on random planar bicubic maps. \nThis presentation
is based on joint work with Philippe Di Francesco\, Bertrand Duplantier an
d Olivier Golinelli.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jules Lamers (IPhT)
DTSTART:20230320T100000Z
DTEND:20230320T110000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/19
DESCRIPTION:Title: The partially (an)isotropic Inozemtsev spin chain\nby Jules L
amers (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\nTraditionally\, (quantum) integrable spin chains are studied under t
he assumption of short-range interactions between the spins\, leading to t
he nearest-neighbour Heisenberg chains. The most famous integrable model w
ith long-range spin interactions is the Haldane--Shastry chain\, whose int
egrable structure was uncovered at IPhT about thirty years ago. The Inozem
tsev spin chain\, which famously made a guest appearance in AdS/CFT integr
ability\, interpolates between the Heisenberg XXX and Haldane--Shastry cha
ins while being exactly solvable throughout. Although widely believe to be
integrable\, the algebraic structure underlying the Inozemtsev chain is n
ot yet known.\n\nOne way to learn about something is to try and deform it.
For spin chains\, it is natural to try and break the SU(2) spin symmetry
('isotropy') down to spin-z symmetry ('partial (an)isotropy') in a way tha
t preserves the key features. In my talk I will present a new long-range s
pin chain: the partially (an)isotropic Inozemtsev chain. It is integrable
in that it has a hierarchy of commuting hamiltonians. In the long-range li
mit it becomes the (known) partially (an)isotropic generalisation of Halda
ne--Shastry\, while in the short-range limit it gives a variant of Heisenb
erg XXZ with nontrivial boundary conditions. Underlying the model is a new
quantum many-body system with spins that generalises the elliptic Ruijsen
aars model.\n\nBased on work in progress with Rob Klabbers (Humboldt U Ber
lin)\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sylvie Corteel (IRIF\, CNRS et Université Paris Cité)
DTSTART:20230327T090000Z
DTEND:20230327T100000Z
DTSTAMP:20260404T100033Z
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 physiqu
e mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\
, Orme des Merisiers.\n\nAbstract\nJ'expliquerai le lien entre pavages par
dominos et suites de partitions\, une idée développée entre autres en
collaboration avec Jérémie Bouttier. Je montrerai comment on peut rajout
er une condition "symplectique" sur ces suites de partitions et définirai
les pavages du triangle Aztec généralisé. Pour certaines formes on ret
rouve le triangle Aztec défini par Philippe Di Francesco. Dans certains c
as on montre que le nombre de pavages a une jolie formule produit. Travail
en collaboration avec Freddie Huang et Christian Krattenthaler. [The talk
was given in English.]\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Valentin Féray (IECL\, CNRS et Université de Lorraine)
DTSTART:20230403T090000Z
DTEND:20230403T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/21
DESCRIPTION:Title: Components of meandric systems and the infinite noodle\nby Va
lentin Féray (IECL\, CNRS et Université de Lorraine) as part of Séminai
re de physique 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 t
he real line in exactly 2n points (up to continuous deformation). In mathe
matical physics terms\, it can be seen as a loop model on a random lattice
. Connected meandric systems are called meanders\, and their enumeration i
s a notorious hard problem in enumerative combinatorics. In this talk\, we
discuss a different question\, raised independently by Goulden--Nica--Pud
er and Kargin: what is the number of connected components $cc(M_n)$ of a u
niform 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
definition of a notion of local convergence for meandric systems\, and the
identification of the “quenched Benjamini--Schramm” limit of $M_n$. T
he latter is the so-called infinite noodle\, a largely not understood perc
olation model recently introduced by Curien\, Kozma\, Sidoravicius and Tou
rnier. \n\nOur main result has also a geometric interpretation\, regarding
the Hasse diagram $H_n$ of the non-crossing partition lattice $NC(n)$: in
formally\, our result implies that\, in $H_n$\, almost all pairs of vertic
es are asymptotically at the same distance from each other. We use here a
connection between $H_n$ and meandric systems discovered by Goulden\, Nica
and Puder. \n\nBased on joint work with Paul Thevenin (University of Vien
na).\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lauren Williams (Harvard University)
DTSTART:20230515T090000Z
DTEND:20230515T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/22
DESCRIPTION:Title: The positive Grassmannian\, the amplituhedron\, and cluster algeb
ras\nby Lauren Williams (Harvard University) as part of Séminaire de
physique mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bâ
t. 774\, Orme des Merisiers.\n\nAbstract\nI will give a gentle introductio
n to the positive Grassmannian and the amplituhedron\, a geometric object
that was introduced in the context of scattering amplitudes in N=4 super Y
ang Mills. I'll then explain some of the connections of the amplituhedron
to combinatorics and to cluster algebras.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sylvain Ribault (IPhT)
DTSTART:20230206T100000Z
DTEND:20230206T110000Z
DTSTAMP:20260404T100033Z
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 mathémati
que IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774\, Orme des M
erisiers.\n\nAbstract\nIn the two-dimensional O(n) and Potts models\, some
observables can be computed as weighted sums over configurations of non-i
ntersecting loops.\n\nI will define weighted sums associated to a large cl
ass of combinatorial maps\, also known as ribbon graphs\, fatgraphs or rot
ation systems. Given a map with $N$ vertices\, this yields a function of t
he moduli of the corresponding punctured Riemann surface\, which I will ca
ll an $N$-point correlation function.\n\nI will conjecture that in the cri
tical limit\, such correlation functions form a basis of solutions of cert
ain conformal bootstrap equations. They include all correlation functions
of the O(n) and Potts models\, and correlation functions that do not belon
g to any known model.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jeanne Scott (Brandeis University)
DTSTART:20230306T100000Z
DTEND:20230306T110000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/24
DESCRIPTION:Title: Clone symmetric function theory\nby Jeanne Scott (Brandeis Un
iversity) as part of Séminaire de physique mathématique IPhT\n\nLecture
held in Salle Claude Itzykson\, Bât. 774\, Orme des Merisiers.\n\nAbstrac
t\nIn 1994 S. Okada introduced a family of non-commutative polynomials sat
isfying a Pieri-type identity which recapitulates the branching rule of R.
Stanley's Young-Fibonacci lattice. More generally\, products of these so
called "clone" Schur functions were shown to obey a non-commutative versio
n of the Littlewood-Richardson identity with structure constants determine
d combinatorially from the Young-Fibonacci lattice structure. \n\nIn this
talk I'll survey Okada's clone theory with the aim of drawing parallels wi
th the (classical) theory of symmetric functions\, the representation theo
ry of the symmetric group\, and the combinatorics of the Young lattice. I'
d also like to use the opportunity to report on some speculative work base
d on discussions with Leonid Petrov: Specifically a new concept of total p
ositivity related to clone Schur functions together with a corresponding "
Stieltjes" moment problem. If there's time\, I'll pose an open problem to
the audience of whether a matrix model can be meaningfully associated to c
ertain clone "tau" functions.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Laurent Chevillard (Laboratoire de physique\, CNRS et ENS de Lyon)
DTSTART:20230605T090000Z
DTEND:20230605T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/25
DESCRIPTION:Title: The phenomenology of fluid turbulence\, and its stochastic repres
entation\nby Laurent Chevillard (Laboratoire de physique\, CNRS et ENS
de Lyon) 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 begin with presenting and illustrating the standard phenomenolog
y of three-dimensional (statistically) isotropic and homogeneous fluid tur
bulence\, which is mainly attributed to Kolmogorov. Then\, while designing
random fields able to reproduce/model the implied intricate spatial struc
ture of kinematic quantities of interest\, and some crucial mechanisms of
the Navier-Stokes equations\, I will explain how come the celebrated Haris
h-Chandra--Itzykson--Zuber integral over the orthogonal group enters in a
probabilistic picture of such a phenomenology. This aspect has been develo
ped with C. Garban\, R. Pereira\, R. Rhodes\, R. Robert and V. Vargas.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jean-Baptiste Fouvry (CNRS\, Institut d'Astrophysique de Paris)
DTSTART:20230612T090000Z
DTEND:20230612T100000Z
DTSTAMP:20260404T100033Z
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 physiq
ue mathématique IPhT\n\nLecture held in Salle Claude Itzykson\, Bât. 774
\, Orme des Merisiers.\n\nAbstract\nMost galaxies harbor a supermassive bl
ack hole in their centre around which orbits a stellar cluster\, the galac
tic nucleus. The unique proximity of the Milky-Way's central black hole\,
SgrA*\, offers an extraordinary opportunity to study such a crowded enviro
nment. Although galactic nuclei are among the densest stellar systems in t
he universe\, the steep potential well generated by the central black hole
allows for efficient long-term orbit-averaged interactions between the st
ars.\n\nUltimately\, this drives the relaxation of the stellar orbits thro
ugh an intricate hierarchy of dynamical processes. In this presentation\,
I will report on recent developments in kinetic theory\, describe efficien
t numerical methods to simulate these dynamics\, and present first quantit
ative applications of these frameworks to constrain SgrA*'s stellar conten
t.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gilles Parez (Université de Montréal)
DTSTART:20230522T120000Z
DTEND:20230522T130000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/27
DESCRIPTION:Title: Entanglement and separability of Rokhsar-Kivelson and resonating
valence-bond states\nby Gilles Parez (Université de Montréal) as par
t of Séminaire de physique mathématique IPhT\n\nLecture held in Salle Cl
aude Itzykson\, Bât. 774\, Orme des Merisiers.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Guillaume Baverez (Humboldt-Universität zu Berlin)
DTSTART:20230619T120000Z
DTEND:20230619T130000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/28
DESCRIPTION:Title: Liouville theory: from Segal's axioms to conformal blocks\nby
Guillaume Baverez (Humboldt-Universität zu Berlin) as part of Séminaire
de physique mathématique IPhT\n\nLecture held in Salle Claude Itzykson\,
Bât. 774\, Orme des Merisiers.\n\nAbstract\nIn Segal's axiomatisation\,
conformal field theories (CFT) can be constructed from (projective) repres
entations of the semigroup of annuli (the set of annuli with parametrised
boundaries endowed with the gluing operation). In the case of the Liouvill
e CFT\, we realise this idea by defining a certain family of Markov proces
ses on the space of distributions on the unit circle. Their generators exi
st as unbounded operators on the Hilbert space and represent the Virasoro
algebra (they are equivalent to the Sugawara construction). \nThis represe
ntation is instrumental in the study of the conformal blocks of the theory
. We can define them using pants decomposition of the underlying surface\,
and associate 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 the conformal blocks are essentially the spectral decomposition of th
ese operators. Their variation with respect to the complex structure of th
e surface is governed by the semigroup\, which is a version of the stateme
nt that conformal blocks are horizontal with respect to the connection def
ined by the stress-energy tensor. This allows us to show that the blocks d
o not depend on the choice of curves representing the pants decomposition.
\nBased on joint and ongoing works with Guillarmou\, Kupiainen\, Rhodes &
Vargas.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jens Hoppe (Technische Universität Braunschweig)
DTSTART:20230626T090000Z
DTEND:20230626T100000Z
DTSTAMP:20260404T100033Z
UID:IPHT-PHM/29
DESCRIPTION:Title: Recent progress in Membrane Theory\, and reduced Yang Mills\n
by Jens Hoppe (Technische Universität Braunschweig) as part of Séminaire
de physique mathématique IPhT\n\nLecture held in Salle Claude Itzykson\,
Bât. 774\, Orme des Merisiers.\n\nAbstract\nExplicit solutions\, and Bae
cklund transformations relating them\,\nwill be presented\, as well as an
Ansatz for the simplest SU(2) matrix model.\n
LOCATION:https://stable.researchseminars.org/talk/IPHT-PHM/29/
END:VEVENT
END:VCALENDAR