Vendredi 4 Juillet 2025, 09:00 à IHP, Amphitheater "Yvonne Choquet-Bruhat", building Perrin, 2nd floor ( https://indico.global/event/14299/ )	WORK-CONF (Workshop or Conference)	gr-qc
Grampa 2025 At Institut Henri Poincaré	DAY 4
Abstract:	This is the second edition of the General Relativity from AMPlitudes Alliance (GRAMPA) workshop, whose primary goal is to support early-career researchers working in the field of scattering amplitudes applied to gravitational theories. The main theme of the workshop is to use of innovative techniques from the field of scattering amplitudes and beyond to study aspects of gravity relevant to upcoming gravitational wave experiments. There will be talks from GRAMPA members on aspects of their work in this field, as well as two short pedagogical lecture series by faculty researchers. The workshop will provide fertile ground for knowledge exchange between communities, foster new collaborations among early career researchers, and map out the shared future research directions of the communities. The structure of the workshop will follow closely our previous meeting: 2 series of lectures in the mornings and seminars in the afternoons.

Mardi 8 Juillet 2025, 14:00 à IHES, Amphithéâtre Léon Motchane	PT-IHES (Séminaire de physique théorique de l'IHES)	hep-th
Dam Thanh Son ( University of Chicago et IHES )	The Spin-two Quasiparticle of the Fractional Quantum Hall Effect
Abstract:	Fractional quantum Hall states are strongly interacting states of two-dimensional electrons moving in a high magnetic field. It has recently been found, theoretically and experimentally, that fractional quantum Hall fluids accommodate a quasiparticle excitations carrying spin equal to 2. I will describe the general theoretical arguments leading to this conclusion. I will also show that the existence of this spin-2 mode explains a strange feature of the numerical data on the spectrum of quantum Hall systems on a sphere.

Mercredi 9 Juillet 2025, 09:30 à IHES, Amphithéâtre Léon Motchane	SEED (Seed Seminar of Mathematics and Physics)	math-ph
Philine Van Vliet ( LPTENS, École Normale Supérieure, Paris, France )	1d Long-range Ising model near the short-range crossover

Mercredi 9 Juillet 2025, 10:30 à IHES, Amphithéâtre Léon Motchane	SEED (Seed Seminar of Mathematics and Physics)	math-ph
Katharina Eichinger ( LMO, Paris-Saclay and Inria ParMA, Orsay )	Lipschitz continuity of diffusion transport maps from a control perspective
Abstract:	Lipschitz transport maps between two measures are useful tools for transferring analytical properties, such as functional inequalities. The most well-known result in this field is Caffarelli’s contraction theorem, which shows that the optimal transport map from a Gaussian to a uniformly log-concave measure is globally Lipschitz. Note that the transfer of analytical properties does not depend on the optimality of the transport map. This is why several works have established Lipschitz bounds for other transport maps, such as those derived from diffusion processes, as introduced by Kim and Milman. Here, we use the control interpretation of the transport vector field inducing the transport map and a coupling strategy to obtain Lipschitz bounds for this map between asymptotically log-concave measures and their Lipschitz perturbations. This talk is based on a joint work with Giovanni Conforti.

Mercredi 9 Juillet 2025, 12:00 à IHES, Amphithéâtre Léon Motchane	SEED (Seed Seminar of Mathematics and Physics)	math-ph
Fanny Eustachon ( CPhT, École polytechnique )	The effective field theory realizations of the perfect fluid
Abstract:	Hydrodynamics is one of the oldest example of field theories, describing the long- range behaviour of many-body systems and its study remained mostly classical. Nevertheless, near zero temperature, quantum fluctuations grow in importance raising the natural question: is there a consistent quantum picture of a perfect fluid at zero temperature? In this talk, I will review the subtly inequivalent Lagrangians realizations of the perfect fluid through the lens of modern effective field theory (EFT). I will then discuss its particularity, naming the presence of an infinitely dimensional symmetry. As we will see, its main implication is the existence of transverse modes with vanishing dispersion relation at the classical level, and an infinitely degenerate spectrum and UV-IR mixing at the quantum level. This is based on a work with G. Cuomo, E. Firat, B. Henning and R. Rattazzi https://arxiv.org/abs/2412.10344.

Mercredi 9 Juillet 2025, 17:00 à LPNHE, Amphitheatre 15, Sorbonne Université, Campus Jussieu ( 17h, café à partir de 16h30 )	SEM-EXCEP (Seminaire exceptionnel)	physics
Giulia Gubitosi ( Associate Professor, Université de Naples, INFN, Chair of COST Action BridgeQG )	Bridging High and Low Energies in Search of Quantum Gravity
Abstract:	The interplay between quantum mechanics and general relativity is one of the most profound open problems in fundamental physics. After decades of purely theoretical investigations, recent experimental advances turned the prospect of a phenomenological approach into a realistic possibility. On the one hand, searches for quantum gravity effects in astrophysical signals constitute nowadays an established field of fundamental research. On the other hand, table-top experiments with quantum systems are now advancing fast towards understanding the role of gravity in quantum systems and testing the possibility that gravity itself is quantized. Investigating the interface between high-energy quantum gravity and quantum aspects of gravity in the low-energy regime, using both theoretical and experimental tools, can provide complementary clues towards the construction of a phenomenologically viable theory of quantum gravity at all scales. In this talk, I will give an overview of the state of the art and key open questions of this research programme and describe the related activities of the COST Action BridgeQG (Bridging high and low energies in search of quantum gravity).

Jeudi 17 Juillet 2025, 11:00 à LPTMC, Jussieu, LPTMC seminar room, towers 13-12, 5th floor, room 523	SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)	cond-mat
Zhengcheng Gu ( The Chinese University of Hong-Kong )	Tensor network simulation in strongly correlated systems: past, present and future
Abstract:	Tensor network states are new kinds of variational wavefunctions that help us to understand quantum phases and phase transitions beyond Landau paradigm. In this talk, I will first review the major development of tensor network simulation in the past two decades. I will introduce the novel concept of long-range entanglement and entanglement renormalization. Then I will discuss the major breakthroughs made by tensor network simulations in recent years. If time permits, I will also mention the relationship between deep learning and tensor network simulation.

Mardi 9 Septembre 2025, 16:00 à LPTHE, library ( Note the unusual time. )	LPTHE-PPH (Particle Physics at LPTHE)	hep-ph
Vasily Sotnikov ( University of Zurich )	TBA

Vendredi 12 Septembre 2025, 14:00 à LPTHE, library	LPTHE-PPH (Particle Physics at LPTHE)	hep-ph
Ekta Chaubey ( University of Bonn )	TBA

Jeudi 2 Octobre 2025, 14:00 à LPTMC, Jussieu, LPTMC seminar room, towers 13-12, 5th floor, room 523	SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)	cond-mat
Nicolas Laflorencie ( LPT Toulouse )	MBL?

Jeudi 6 Novembre 2025, 14:00 à LPTMC, Jussieu, LPTMC seminar room, towers 13-12, 5th floor, room 523	SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)	cond-mat
Jérôme Dubail ( CESQ Strasbourg )	TBA

Jeudi 15 Janvier 2026, 14:00 à LPTMC, Jussieu, LPTMC seminar room, towers 13-12, 5th floor, room 523	SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)	cond-mat
Evgeny Stepanov ( CPhT )	TBA