Lundi 2 Novembre 2026, 10:30 à LPTHE, LPTHE library	SEM-LPTHE (Séminaire du LPTHE)	hep-th
Anders Wallberg ( CERN and EPFL )	Time-Dependent Integrability from Gauge Theory
Abstract:	Solvable time-dependent systems provide important setups for studying non- equilibrium physics, where exact results are rare. This takl will focus on classical integrable systems, which are known to be constructible from a 4D Chern-Simons Theory. By appropriately generalising this gauge theory, Iwill construct a zoo of different time-dependent integrable models, most of which were previously unknown, and show that they are solvable by the inverse scattering method. I show how these systems have various connections to condensed matter physics, RG-flow and theories of gravity.

Lundi 2 Novembre 2026, 11:00 à IPHT, Salle Claude Itzykson, Bât. 774	IPHT-MAT (Séminaire de matrices, cordes et géométries aléatoires)	physics
Yuan Miao	The Onsager algebra in quantum lattice models
Abstract:	Abstract:The Onsager algebra plays an important role in exactly solvable models. One of the most notable examples is the solution to the 2D classical Ising model using the Onsager algebra by Lars Onsager in 1944. I will explain the appearance of the Onsager algebra in various quantum lattice models, and report the recent results on the Onsager algebra as the symmetry of the 6-vertex model at root of unity values of anisotropy. The talk is based on a series of work in arXiv: 2606.25660, 2103.14569, 2012.10224 and work in progress.

Lundi 2 Novembre 2026, 14:00 à IHES, Amphithéâtre Léon Motchane	PT-IHES (Séminaire de physique théorique de l'IHES)	hep-th
Alexander Turbiner ( ICN-UNAM, Mexico – Stony Brook Univ., USA – CRM, Canada )	Exact-Solvability of Superintegrable Systems
Abstract:	All, so far known explicitly two-dimensional quantum superintegrable systems in flat space are exactly solvable with spectra linear in quantum numbers (in agreement with the Montreal Conjecture by Tempesta-Turbiner-Winternirz (2001)). Their eigenfunctions are bivariate orthogonal polynomials in invariants of the (discrete) symmetry group. It includes the Smorodinsky-Winternitz potentials I-IV (or the Holt potential), the Fokas-Lagerstrom model, the 3-body Calogero (equivalently, A2 rational) and the Wolfes (equivalently, G2 rational, or I6) models, and the Tremblay-Turbiner-Winternitz system with integer index k=1,2,3,4. They have hidden (Lie) algebraic structure g(k) with various k, and they possess a (finite order) polynomial algebras of integrals generated by the Hamiltonian, two algebraically-independent integrals and their commutator.

Mardi 3 Novembre 2026, 14:00 à LPENS, LPENS Library - E239	LPENS-PH (LPENS Particle physics phenomenology and cosmology)	hep-th
Anders Wallberg	Orientifolds, Crosscaps & Integrability: N=4 SYM on Projective Space
Abstract:	Orientifold planes are enigmatic objects in string theory: they have no independent localised dynamical degrees of freedom and can carry negative tension, while their non-perturbative description remains challenging. I will discuss a setting in which protected observables provide non-perturbative data in the presence of an orientifold: N=4 SYM on RP4, defined by combining an antipodal identification on spacetime with an R-symmetry reflection and charge conjugation of the SU(N) gauge group. At weak coupling, planar tree-level one- point functions are described by spin-chain crosscap overlaps, providing evidence for preserved integrability. At strong coupling, I will identify the associated classical worldsheet crosscap and probe O1-plane, and discuss the quantum crosscap in the pp-wave limit. Supersymmetric localisation yields finite-coupling half-BPS one-point functions; time permitting, I will explain the matrix model and discuss its weak-coupling and BMN limits.

Mercredi 4 Novembre 2026, 10:30 à IHES, Amphithéâtre Léon Motchane ( online seminar )	SEED (Seed Seminar of Mathematics and Physics)	hep-th
Suvrat Raju ( ICTS )	Large Language Models and Physics
Abstract:	We will start with a brief technical overview of Large Language Models and then discuss their impact on the theoretical sciences. We will summarize the results of a recent study "TheoPhysEval" (https://arxiv.org/abs/2610.16733) where we evaluated AI agents on unsolved physics problems. The talk is aimed at initiating a broader discussion on how physics pedagogy and research must evolve in light of recent technological advances.

Mercredi 4 Novembre 2026, 11:00 à LPENS, E239 (Theoretical physics library)	LPENS-BQ (Balades Quantiques de le LPENS)	cond-mat.stat-mech
Marco Schiro	From non-reciprocal to active quantum matter via engineered dissipation
Abstract:	Non-reciprocal interactions and activity are ubiquitous in classical systems far from equilibrium, from living and soft matter to ecology and optics. They give rise to distinctive collective phenomena and phase transitions. In this talk, I will discuss how non-reciprocal and active dynamics can be realised in quantum systems through engineered coupling to an external environment. I will first present our results on interacting non-reciprocal fermions and their dissipative phase transitions. I will then introduce three minimal models of an active quantum particle, exploring how activity manifests in the quantum regime.

Mercredi 4 Novembre 2026, 11:30 à IJCLAB, 100/2-A201 - Salle A201 (IJCLab) ( https://indico.ijclab.in2p3.fr/event/14514/ )	IJCLAB-HEP (Particle Physics Seminars at IJCLab)	hep-ph
Jani Penttala ( IJCLab )	Energy Correlators: A New Lens on Nuclear Structure
Abstract:	A central goal of particle physics is to understand how quarks and gluons are bound together to form nucleons and nuclear matter. One promising class of observables for this task is energy correlators, which have gained renewed attention in recent years due to their clean experimental and theoretical properties. Instead of measuring individual particles, energy correlators focus on the angular distribution of the energy flow and are often less sensitive to nonperturbative final-state hadronization. In this talk, I will discuss the role of energy correlators in probing nuclear structure, focusing on transverse momentum distributions, jet substructure, and gluon saturation. I will also demonstrate how energy correlators can provide us with complementary information compared to the standard particle production cross sections and discuss their potential for advancing our understanding of nuclear structure at the LHC and the future Electron-Ion Collider.

Mercredi 4 Novembre 2026, 11:45 à IHES, Amphithéâtre Léon Motchane	SEED (Seed Seminar of Mathematics and Physics)	math
Thomas Mordant ( LMO )	A counterexample to the Jacobian conjecture in dimension three
Abstract:	The Jacobian conjecture states that for any polynomial map from \mathbb{C}^n to itself, if it is everywhere a local diffeomorphism, then it admits a polynomial global inverse. In this talk, I will present the three-dimensional counterexample to this conjecture posted by L. Alpöge on X and credited to Claude. After stating the conjecture and the counterexample, I will explain the geometric interpretation of the counterexample which was posted by A. Jiang and credited to ChatGPT. Finally I will give some observations about the history of the conjecture and its significance.

Jeudi 5 Novembre 2026, 10:00 à IHP, Choquet Bruhat	RENC-THEO (Rencontres Théoriciennes)	hep-th
Thomas Mertens ( Ghent university )	Falling through the horizon of a quantum black hole
Abstract:	In this talk, I will construct a definition of diff-invariant bulk observables in lower-dimensional JT gravity, and argue for its uniqueness. I will use these to construct bulk observer worldlines, their detectors and discuss the resulting physical implications. For the case of observers falling into a quantum black hole, I will discuss how quantum gravity effects lead to a violation of the equivalence principle, but the absence of a firewall. Including wormholes into the calculation causes the classical horizon to be operationally inaccessible and the interior effectively sealed off from the outside. Based on 2607.03344 and 2609.05164.

Vendredi 6 Novembre 2026, 13:00 à LPENS, Conf IV	ENS-BIOPHYS (ENS Biophysics Seminar)	physics.bio-ph
Nikolas Claussen ( Princeton University )	Shape control with active stress
Abstract:	Morphogenesis is the process by which biological systems sculpt their shapes, for example, during embryonic development. Physical constraints from mechanics and geometry are essential to understanding this process; conversely, “living matter” exhibits new physical phenomena. To change shape, cells actively generate mechanical stress using motor molecules. We describe a recent theoretical framework for the mechanics and morphogenesis of epithelia (arXiv 2601.08968 and 2601.14467). Tools from (discrete) Riemannian geometry show how local, active tensions control tissue shape, and how tissues can “flow” without becoming a fluid. Morphogenesis also takes place at the intracellular scale. We discuss ongoing work to simulate strongly deforming membranes and biomolecular condensates, using automatic differentiation, a core machine-learning technique, to reverse-engineer the processes that give rise to observed shapes (arXiv 2610.02566). We outline future directions on unifying the “physical” geometry of morphogenesis with the “internal” geometry of the Waddington landscapes that govern cell differentiation.

Lundi 9 Novembre 2026, 10:30 à LPTHE, LPTHE library	SEM-LPTHE (Séminaire du LPTHE)	hep-th
Dmitri Bykov	TBA

Lundi 9 Novembre 2026, 14:00 à IHES, Amphithéâtre Léon Motchane ( Séminaire Géométrie et groupes discrets )	MATH-IHES (TBA)	math
Antoine Song ( Caltech et IHES )	Representations and Harmonic Maps into Spheres
Abstract:	I will discuss some recent progress on harmonic maps from surfaces to spheres which are energy minimizing representatives of orthogonal representations. What can be said about their shapes and their limit geometry as the dimension of the representations grows to infinity? This is partly joint with Riccardo Caniato and Xingzhe Li.

Lundi 9 Novembre 2026, 16:00 à IHES, Amphithéâtre Léon Motchane ( Séminaire Géométrie et groupes discrets )	MATH-IHES (TBA)	math
Konstantinos Tsouvalas ( Jagiellonian University )	Combinations of Non-Archimedean Discrete Groups
Abstract:	Chatterji and Venkataramana, motivated by Nori's problem, asked for a real algebraic semisimple Lie group G and a simple Lie subgroup H of G, whether a Zariski-dense discrete subgroup of G, intersecting H in a lattice, is itself a lattice in G. After discussing what is known related to this question and Nori's problem, we will address a similar version of this question for the k-points of semisimple groups defined over a non-Archimedean local field k, and provide examples for which a positive answer fails. This is based on a combination theorem for discrete subgroups of matrix groups over discretely valued fields. We will also discuss a construction of non-Fuchsian hyperbolic groups that quasi-isometrically embed as subgroups of matrix groups over a discretely valued field.

Mardi 10 Novembre 2026, 14:00 à LPTHE, Library ( In the library but also on Zoom https://cern.zoom.us/j/66153921648? pwd=Us05borvD1FZY4vi4QaNha8frGw9et.1 )	LPTHE-PPH (Particle Physics at LPTHE)	hep-ph
Giulia Zanderighi ( Max-Planck-Institute for Physics, Garching )	TBA
Abstract:	TBA

Jeudi 12 Novembre 2026, 11:00 à LPENS, E239 (Theoretical physics library)	LPENS-BQ (Balades Quantiques de le LPENS)	cond-mat.stat-mech
Michael Sonner ( University of California, Berkeley )	Multibath Influence Matrices: Universal Scaling from Real-Time Dynamics
Abstract:	We introduce a framework for describing the real-time dynamics of quantum impurity models out of equilibrium which is based on the influence matrix approach. By replacing the dynamical map of a large fermionic quantum environment with an effective semi-group influence matrix (SGIM) which acts on a reduced auxiliary space, we overcome the limitations of previous proposals, achieving high accuracy at long evolution times, which we demonstrate by computing the spectral function of the single impurity Anderson model. Once the effective compressed baths are obtained, they can then be used as building blocks, allowing the study of more complex models such as the two impurity Anderson model. At a coupling strength between the two dots comparable to the Kondo scale this model is known to host a two channel Kondo like non-fermi liquid point. We study this critical point by considering dynamical observables such as the relaxation time after a quench and the work exerted on a ramp through the critical point exhibiting Kibble Zurek like physics. Finally I'll discuss applications of this method to non-equilibrium dynamical mean field theory.

Jeudi 12 Novembre 2026, 11:00 à LPTHE, bibliothèque du LPTHE, tour 13-14, 4eme étage	SEM-DARBOUX (Séminaire Darboux - physique théorique et mathématiques)	hep-th
Piet Lammers ( Sorbonne )	TBA

Vendredi 13 Novembre 2026, 13:00 à LPENS, Conf IV	ENS-BIOPHYS (ENS Biophysics Seminar)	physics.bio-ph
Min Wu ( Worcester Polytechnic Institute )	TBA

Mercredi 18 Novembre 2026, 10:30 à LPTHE, LPTHE library	WORK-CONF (Workshop or Conference)	math-ph
Tba	SEED

Mercredi 18 Novembre 2026, 11:00 à IJCLAB, 100/2-A201 - Salle A201 (IJCLab) ( https://indico.ijclab.in2p3.fr/event/14513/ )	IJCLAB-HEP (Particle Physics Seminars at IJCLab)	hep-ph
Patricia Gimeno-Estivill ( University of Jyväskylä )	Diffractive TMDs and D meson production in UPCs in the CGC formalism
Abstract:	Using the Color Glass Condensate effective theory, we study the diffractive production of a massive quark-antiquark pair accompanied by a gluon in coherent photon-nucleus collisions at high energy. This partonic configuration provides the leading twist contribution to the cross section in the correlation limit where two of the partons are hard and nearly back to back in the transverse plane, while the third one is semi-hard, with a transverse momentum of the order of the nuclear saturation momentum. We consider two scenarios: (i) a hard quark-antiquark pair together with a semi-hard gluon; in this case we demonstrate transverse momentum dependent (TMD) factorisation with a mass-dependent "hard" factor and the standard expression for the gluon diffractive TMD, and (ii) a hard antiquark-gluon pair and a semi-hard quark; in this case we find TMD factorisation with a mass-independent "hard" factor and a mass-dependent quark diffractive TMD, which represents a new result. Additionally, based on these results we present a preliminary phenomenological study of diffractive D0 meson production in UPCs at LHC.

Mercredi 18 Novembre 2026, 11:45 à LPTHE, LPTHE library	WORK-CONF (Workshop or Conference)	math-ph
Tba	SEED

Jeudi 19 Novembre 2026, 10:00 à IHP, Choquet Bruhat	RENC-THEO (Rencontres Théoriciennes)	hep-th
Max Wiesner ( Hamburg University )	TBA

Mardi 24 Novembre 2026, 10:45 à LPTMC, campus Jussieu, couloir 12-13, 5ème étage, salle 5-23	SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)	cond-mat
Léo Touzo ( U. Chicago )	TBA

Mercredi 25 Novembre 2026, 11:00 à LPTHE, LPTHE library	SEM-LPTHE (Séminaire du LPTHE)	hep-th
Claudia Rella ( IHES )	TBA

Jeudi 26 Novembre 2026, 11:00 à IHES, Amphithéâtre Léon Motchane	MATH-IHES (TBA)	math
Marco Volpe ( University of Mainz )	The Stratified Shape
Abstract:	In this talk, I will try to address the question of how to do algebraic topology with stratified spaces and schemes in a meaningful way. I will begin by recalling and motivating some of the main historical attempts to approach this question, both in topology and in algebraic geometry, passing through the work of Nash, Quinn, Siebenmann, Edwards–Hastings, Deligne, and, more recently, Lurie and Barwick–Glasman–Haine. I will then propose my own answer, based on a construction I call the stratified shape. Time permitting, I will discuss some applications of the stratified shape to proper homotopy theory (joint with Georg Lehner), homology manifolds (joint with Markus Land), and a generalization of Lurie's exodromy equivalence (joint with Peter Haine and Guglielmo Nocera).

Jeudi 26 Novembre 2026, 17:00 à UFR-PHYS-SU, Amphi 25 Campus Pierre-et-Marie-Curie, Jussieu	CPMC (Colloquium Pierre et Marie Curie)	physics|quant-ph
Daniel Estève ( Groupe Quantronique, SPEC, CEA-Saclay )	From the first superconducting quantum circuits to quantum computing and single spin quantum sensing
Abstract:	The demonstration in the mid-1980s at Berkeley that an electrical circuit can obey the laws of quantum mechanics earned John Clarke, John Martinis and Michel Devoret the 2025 Nobel prize in Physics. The goal of the Quantronics group established at CEA Saclay was to implement such quantum electrical circuits. I will describe some of them, notably the “Single Cooper Pair Box” which forms the basis of the superconducting quantum bits most commonly used today in quantum processors, as well as a single spin sensor based on a single microwave photon detector.

Lundi 30 Novembre 2026, 10:30 à LPTHE, LPTHE library	SEM-LPTHE (Séminaire du LPTHE)	hep-th
Fiona Seibold ( EPFL )	TBA

Mardi 1 Décembre 2026, 10:45 à LPTMC, campus Jussieu, couloir 12-13, 5ème étage, salle 5-23	SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)	cond-mat
Bo Han ( Cologne )	TBA

Mercredi 2 Décembre 2026, 10:30 à IHES, Amphithéâtre Léon Motchane	SEED (Seed Seminar of Mathematics and Physics)	math-ph
Tba	TBA

Mercredi 2 Décembre 2026, 11:45 à IHES, Amphithéâtre Léon Motchane	SEED (Seed Seminar of Mathematics and Physics)	math-ph
Tba	TBA

Mercredi 2 Décembre 2026, 14:00 à IHES, Amphithéâtre Léon Motchane ( Cours de l'IHES )	MATH-IHES (TBA)	math
Marc Burger ( ETH Zürich )	Two Applications of the Arithmetic Margulis Lemma (1/4)
Abstract:	This course has two parts. In the first we will define a general notion of integer point in a higher Teichmüller space and two invariants thereof, the arithmetic dimension and the arithmetic height. The aim is to show finiteness, modulo the mapping class group action, of the number of integer points for which both invariants are bounded. In the second part we will give the main steps leading to the recent result of Frączyk, Hurtado and Raimbault, stating that the topological complexity of an arithmetic locally symmetric space is bounded by its volume. Both parts rely on the arithmetic Margulis lemma proven by the same authors as a consequence of Breuillard's height gap theorem.