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Tuesday 14 May 2024, 10:30 at IHES, Amphithéâtre Léon Motchane MATH-IHES (TBA) math

Albert Schwarz ( University of California at Davis & IHES ) Quantitative Hydrodynamic Limit for Interacting Particle Systems: Panorama and Recent Advances (4/4)

Abstract: The course is based on a minibook that will be published by Springer. The text below is a shortened preface to this book. In the conventional exposition of quantum mechanics, we work in Hilbert space and examine operators within this space. Self-adjoint operators are associated with physical quantities. Physicists predominantly use this methodology, however, it has its limitations. In this course we explore alternative viewpoints; our exposition does not depend on standard textbooks. We consider the algebraic approach, where the initial point is an algebra of observables, an associative algebra with involution, in which the self-adjoint elements are observables. This approach is nearly as old as quantum mechanics itself. In addition, we discuss the geometric approach, where the initial point is a set of states. This viewpoint was advocated in my recent papers; it is much more general. We demonstrate within the framework of this approach that quantum mechanics can be viewed as classical mechanics where our devices permit us to observe only a subset of physical quantities. Furthermore, we show that using this approach we can construct a wide class of physical theories that generalize quantum mechanics. We highlight that the emergence of probabilities in quantum theory can be derived from decoherence caused by adiabatic interaction with a random environment. We underscore that the concept of a particle is not primary in quantum theory. If the theory is translation-invariant we define particles as elementary excitations of the ground state. Quasiparticles are elementary excitations of any translation-invariant state. We analyze the concept of scattering but we do not utilize the concept of a field and do not assume locality and Poincare invariance. We discuss not only the conventional scattering matrix (related to scattering cross-sections) but also the concept of an inclusive scattering matrix, which is closely related to the concept of inclusive scattering cross-sections. Scattering matrix can be expressed in terms of Green's functions by the well-known formula belonging to Lehmann, Symanczyk, and Zimmermann, and the inclusive scattering matrix can be expressed in terms of generalized Green's functions, which first appeared in nonequilibrium statistical physics in Keldysh formalism. As a concrete realization of the geometric approach, we describe the formalism of L-functionals where states are represented by non-linear functionals corresponding to positive functionals on Weyl and Clifford algebras (to states in the algebraic approach). L-functionals can be applied to solve the infrared problem in quantum electrodynamics.

Tuesday 14 May 2024, 11:00 at LPTMS, Salle des séminaires du FAST et du LPTMS, bâtiment Pascal n°530 LPTMS (Séminaire du Laboratoire de Physique Théorique et Modèles Statistiques (Orsay)) cond-mat.stat-mech

Clément Sire ( LPT Toulouse ) When poor little fish are confronted with AI, robot-fish, virtual reality, and drones

Abstract: After introducing the collective behaviors observed in fish schools, I will outline a methodology for quantitatively measuring social interactions (attraction/repulsion; alignment) within animal groups. The reconstructed interactions can then be directly implemented in analytical models which quantitatively reproduce the collective motion of fish. I will also briefly address an alternative machine learning approach designed to produce realistic fish trajectories. In the latter part of the presentation, I will explore various applications of such analytical or machine learning behavioral models in the context of robotic and drone platforms, and a virtual reality setup… for fish! In particular, our robot-fish and VR setups constitute original and powerful tools to study the social dynamics of fish and their response to controlled perturbations.

Wednesday 15 May 2024, 13:30 at DPT-PHYS-ENS, ConfIV (E244) - Dépt de Physique de l'ENS - 24 rue Lhomond 75005 PARIS COLLOQUIUM-ENS (Colloquium of the Physics Department of ENS) physics

Raymond E. Goldstein TBA

Abstract: TBA

Tuesday 21 May 2024, 11:00 at LPTMS, Salle des séminaires du FAST et du LPTMS LPTMS (Séminaire du Laboratoire de Physique Théorique et Modèles Statistiques (Orsay)) cond-mat.stat-mech

Ricardo Marino ( Google Paris ) TBA

Wednesday 22 May 2024, 12:45 at LPENS, 3 rue d'Ulm FORUM-ENS (Forum de Physique Statistique @ ENS) cond-mat.stat-mech

Manon Michel ( Universite Clermont-Auvergne ) TBA

Abstract: TBA

Thursday 23 May 2024, 11:00 at LPTHE, bibliothèque du LPTHE, tour 13-14, 4eme étage SEM-DARBOUX (Séminaire Darboux - physique théorique et mathématiques) hep-th|math.DG

Eleanora Di Nezza ( IMJ ) TBA

Thursday 23 May 2024, 14:00 at LPTMC, LPTMC seminar room, Jussieu, towers 12-13, 5th floor, room 523 SEM-EXCEP (Seminaire exceptionnel) cond-mat

Nicolas Bergeal ( ESPCI ) Mesures de densité superfluide dans les supraconducteurs 2D

Abstract: TBA

Monday 27 May 2024, 13:30 at LPENS, U209 (29 rue d'Ulm) LPENS-MDQ (Séminaire Matériaux et Dispositifs Quantiques du LPENS) cond-mat

Sanchar Sharma TBA

Wednesday 29 May 2024, 12:45 at LPENS, 3 rue dUlm, College de France FORUM-ENS (Forum de Physique Statistique @ ENS) cond-mat.stat-mech

Pierfrancesco Urbani ( IPHT ) TBA

Abstract: T

Monday 3 June 2024, 11:00 at IPHT, Salle Claude Itzykson, Bât. 774 IPHT-STA (Séminaire de Physique Statistique, CEA/Saclay) cond-mat

Guilhem Semerjian ( LPENS ) TBA

Abstract: TBA

Tuesday 4 June 2024, 11:00 at LPTMS, Salle des séminaires du FAST et du LPTMS, bâtiment Pascal n°530 LPTMS (Séminaire du Laboratoire de Physique Théorique et Modèles Statistiques (Orsay)) cond-mat.stat-mech

Alexios P. Polychronakos ( CUNY New York ) TBA

Wednesday 5 June 2024, 13:30 at DPT-PHYS-ENS, ConfIV (E244) - Dépt de Physique de l'ENS - 24 rue Lhomond 75005 PARIS COLLOQUIUM-ENS (Colloquium of the Physics Department of ENS) physics

Guy Perrin TBA

Wednesday 5 June 2024, 13:45 at LPENS, 3 rue d'Ulm FORUM-ENS (Forum de Physique Statistique @ ENS) cond-mat.stat-mech

Guy Bunin ( Technion ) TBA

Abstract: TBA

Tuesday 11 June 2024, 11:00 at LPTMS, Salle des séminaires du FAST et du LPTMS, bâtiment Pascal n°530 LPTMS (Séminaire du Laboratoire de Physique Théorique et Modèles Statistiques (Orsay)) cond-mat.stat-mech

Ritesh Bhola ( Tata institute, Mumbai ) TBA

Wednesday 12 June 2024, 14:15 at IPHT, Salle Claude Itzykson, Bât. 774 IPHT-MAT (Séminaire de matrices, cordes et géométries aléatoires) hep-th

Victor Rodriguez ( Princeton ) TBD

Abstract: TBD

Wednesday 19 June 2024, 12:45 at LPENS, 3 rue dUlm FORUM-ENS (Forum de Physique Statistique @ ENS) cond-mat.stat-mech

Ananda Roy ( Rutgers University ) TBA

Abstract: TBA

Wednesday 19 June 2024, 14:15 at IPHT, Salle Claude Itzykson, Bât. 774 IPHT-MAT (Séminaire de matrices, cordes et géométries aléatoires) hep-th

Fridrik Gautason TBD

Abstract: TBD

Tuesday 25 June 2024, 11:00 at LPTMS, Salle des séminaires du FAST et du LPTMS LPTMS (Séminaire du Laboratoire de Physique Théorique et Modèles Statistiques (Orsay)) cond-mat.stat-mech

Anton Souslov ( University of Cambridge ) TBA

Thursday 27 February 2025, 14:00 at IJCLAB, A201 NUC-THEO (Séminaire de physique nucléaire théorique) nucl-th

Benjamin Bally ( CEA Saclay ) Coupling nuclear structure and relativistic hydrodynamic calculations: collectivity in small systems

Abstract: Whether or not femto-scale droplets of quark-gluon plasma (QGP) are formed in so-called small systems at high-energy colliders is a pressing question in the phenomenology of the strong interaction. For proton-proton or proton-nucleus collisions the answer is inconclusive due to the large theoretical uncertainties plaguing the description of these processes. While upcoming data on collisions of $^{16}$O nuclei may mitigate these uncertainties in the near future, here we demonstrate the unique possibilities offered by complementing $^{16}$O+$^{16}$O data with collisions of $^{20}$Ne ions. We couple both NLEFT and PGCM ab initio descriptions of the structure of $^{20}$Ne and $^{16}$O to hydrodynamic simulations of $^{16}$O+$^{16}$O and $^{20}$Ne+$^{20}$Ne collisions at high energy. We isolate the imprints of the bowling-pin shape of $^{20}$Ne on the collective flow of hadrons, which can be used to perform quantitative tests of the hydrodynamic QGP paradigm. In particular, we predict that the elliptic flow of $^{20}$Ne+$^{20}$Ne collisions is enhanced by as much as 1.170(8)(30) for NLEFT and 1.139(6)(39)for PGCM relative to $^{16}$O+$^{16}$O collisions for the 1\% most central events. At the same time, theoretical uncertainties largely cancel when studying relative variations of observables between two systems. This demonstrates a method based on experiments with two light-ion species for precision characterizations of the collective dynamics and its emergence in a small system.
Attachments:
Abstract.pdf (144023 bytes)

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Tuesday 14 May 2024, 10:30 at IHES, Amphithéâtre Léon Motchane	MATH-IHES (TBA)	math
Albert Schwarz ( University of California at Davis & IHES )	Quantitative Hydrodynamic Limit for Interacting Particle Systems: Panorama and Recent Advances (4/4)
Abstract:	The course is based on a minibook that will be published by Springer. The text below is a shortened preface to this book. In the conventional exposition of quantum mechanics, we work in Hilbert space and examine operators within this space. Self-adjoint operators are associated with physical quantities. Physicists predominantly use this methodology, however, it has its limitations. In this course we explore alternative viewpoints; our exposition does not depend on standard textbooks. We consider the algebraic approach, where the initial point is an algebra of observables, an associative algebra with involution, in which the self-adjoint elements are observables. This approach is nearly as old as quantum mechanics itself. In addition, we discuss the geometric approach, where the initial point is a set of states. This viewpoint was advocated in my recent papers; it is much more general. We demonstrate within the framework of this approach that quantum mechanics can be viewed as classical mechanics where our devices permit us to observe only a subset of physical quantities. Furthermore, we show that using this approach we can construct a wide class of physical theories that generalize quantum mechanics. We highlight that the emergence of probabilities in quantum theory can be derived from decoherence caused by adiabatic interaction with a random environment. We underscore that the concept of a particle is not primary in quantum theory. If the theory is translation-invariant we define particles as elementary excitations of the ground state. Quasiparticles are elementary excitations of any translation-invariant state. We analyze the concept of scattering but we do not utilize the concept of a field and do not assume locality and Poincare invariance. We discuss not only the conventional scattering matrix (related to scattering cross-sections) but also the concept of an inclusive scattering matrix, which is closely related to the concept of inclusive scattering cross-sections. Scattering matrix can be expressed in terms of Green's functions by the well-known formula belonging to Lehmann, Symanczyk, and Zimmermann, and the inclusive scattering matrix can be expressed in terms of generalized Green's functions, which first appeared in nonequilibrium statistical physics in Keldysh formalism. As a concrete realization of the geometric approach, we describe the formalism of L-functionals where states are represented by non-linear functionals corresponding to positive functionals on Weyl and Clifford algebras (to states in the algebraic approach). L-functionals can be applied to solve the infrared problem in quantum electrodynamics.

Tuesday 14 May 2024, 11:00 at LPTMS, Salle des séminaires du FAST et du LPTMS, bâtiment Pascal n°530	LPTMS (Séminaire du Laboratoire de Physique Théorique et Modèles Statistiques (Orsay))	cond-mat.stat-mech
Clément Sire ( LPT Toulouse )	When poor little fish are confronted with AI, robot-fish, virtual reality, and drones
Abstract:	After introducing the collective behaviors observed in fish schools, I will outline a methodology for quantitatively measuring social interactions (attraction/repulsion; alignment) within animal groups. The reconstructed interactions can then be directly implemented in analytical models which quantitatively reproduce the collective motion of fish. I will also briefly address an alternative machine learning approach designed to produce realistic fish trajectories. In the latter part of the presentation, I will explore various applications of such analytical or machine learning behavioral models in the context of robotic and drone platforms, and a virtual reality setup… for fish! In particular, our robot-fish and VR setups constitute original and powerful tools to study the social dynamics of fish and their response to controlled perturbations.

Wednesday 15 May 2024, 13:30 at DPT-PHYS-ENS, ConfIV (E244) - Dépt de Physique de l'ENS - 24 rue Lhomond 75005 PARIS	COLLOQUIUM-ENS (Colloquium of the Physics Department of ENS)	physics
Raymond E. Goldstein	TBA
Abstract:	TBA

Wednesday 22 May 2024, 12:45 at LPENS, 3 rue d'Ulm	FORUM-ENS (Forum de Physique Statistique @ ENS)	cond-mat.stat-mech
Manon Michel ( Universite Clermont-Auvergne )	TBA
Abstract:	TBA

Thursday 23 May 2024, 11:00 at LPTHE, bibliothèque du LPTHE, tour 13-14, 4eme étage	SEM-DARBOUX (Séminaire Darboux - physique théorique et mathématiques)	hep-th\|math.DG
Eleanora Di Nezza ( IMJ )	TBA

Thursday 23 May 2024, 14:00 at LPTMC, LPTMC seminar room, Jussieu, towers 12-13, 5th floor, room 523	SEM-EXCEP (Seminaire exceptionnel)	cond-mat
Nicolas Bergeal ( ESPCI )	Mesures de densité superfluide dans les supraconducteurs 2D
Abstract:	TBA

Monday 27 May 2024, 13:30 at LPENS, U209 (29 rue d'Ulm)	LPENS-MDQ (Séminaire Matériaux et Dispositifs Quantiques du LPENS)	cond-mat
Sanchar Sharma	TBA

Monday 3 June 2024, 11:00 at IPHT, Salle Claude Itzykson, Bât. 774	IPHT-STA (Séminaire de Physique Statistique, CEA/Saclay)	cond-mat
Guilhem Semerjian ( LPENS )	TBA
Abstract:	TBA

Wednesday 12 June 2024, 14:15 at IPHT, Salle Claude Itzykson, Bât. 774	IPHT-MAT (Séminaire de matrices, cordes et géométries aléatoires)	hep-th
Victor Rodriguez ( Princeton )	TBD
Abstract:	TBD

Thursday 27 February 2025, 14:00 at IJCLAB, A201	NUC-THEO (Séminaire de physique nucléaire théorique)	nucl-th
Benjamin Bally ( CEA Saclay )	Coupling nuclear structure and relativistic hydrodynamic calculations: collectivity in small systems
Abstract:	Whether or not femto-scale droplets of quark-gluon plasma (QGP) are formed in so-called small systems at high-energy colliders is a pressing question in the phenomenology of the strong interaction. For proton-proton or proton-nucleus collisions the answer is inconclusive due to the large theoretical uncertainties plaguing the description of these processes. While upcoming data on collisions of $^{16}$O nuclei may mitigate these uncertainties in the near future, here we demonstrate the unique possibilities offered by complementing $^{16}$O+$^{16}$O data with collisions of $^{20}$Ne ions. We couple both NLEFT and PGCM ab initio descriptions of the structure of $^{20}$Ne and $^{16}$O to hydrodynamic simulations of $^{16}$O+$^{16}$O and $^{20}$Ne+$^{20}$Ne collisions at high energy. We isolate the imprints of the bowling-pin shape of $^{20}$Ne on the collective flow of hadrons, which can be used to perform quantitative tests of the hydrodynamic QGP paradigm. In particular, we predict that the elliptic flow of $^{20}$Ne+$^{20}$Ne collisions is enhanced by as much as 1.170(8)(30) for NLEFT and 1.139(6)(39)for PGCM relative to $^{16}$O+$^{16}$O collisions for the 1\% most central events. At the same time, theoretical uncertainties largely cancel when studying relative variations of observables between two systems. This demonstrates a method based on experiments with two light-ion species for precision characterizations of the collective dynamics and its emergence in a small system.
Attachments:	Abstract.pdf (144023 bytes)