Pantheon SEMPARIS Le serveur des séminaires parisiens Paris

The SEMPARIS seminar webserver hosts annoucements of all seminars taking place in Paris area, in all topics of physics, mathematics and computer science. It allows registered users to receive a selection of announcements by email on a daily or weekly basis, and offers the possibility to archive PDF or Powerpoint files, making it available to the scientific community.   [ More information ]


Upcoming Seminars [Next 30 ]
[ scheduler view ]

Wednesday 24 January 2018, 14:15 at IPHT, Salle Claude Itzykson, Bât. 774 IPHT-MAT (Séminaire de matrices, cordes et géométries aléatoires) hep-th
Juan Diaz Dorronsoro ( ITF - KU Leuven ) Towards an explicit model of large field inflation
Abstract: Antibranes are the usual suspects of de Sitter model building in string theory. They have been extensively used in flux compactifications to uplift anti de Stitter vacua to metastable de Sitter minima. In this talk I will start by briefly reviewing some recent results on the (non-)existence of antibrane solutions as the ones used in model building. Afterwards I will present a model for inflation based on a series of antibrane annihilation processes, which provides a concrete string theory realization of the unwinding inflation mechanism. I will argue that the model succeeds in providing a large field excursion for the inflaton while satisfying the constraints required to maintain a consistent effective field theory.

Thursday 25 January 2018, 10:00 at LPTHE, IMPMC, salle 401, tour 22-23, 4eme étage
( Beware, unusual location ! )
RENC-THEO (Rencontres Théoriciennes) hep-th
Amos Yarom ( Technion ) The large D limit of holographic turbulence
Abstract: I will discuss a recent attempt at gaining a handle over turbulent behaviour of fluids by appealing to the gauge gravity duality in the limit where the number of dimensions becomes very large. We will see that in this limit the gauge gravity duality simplifies and that the dynamics of the system are encoded in the large d limit of the hydrodynamic equations of motion.

Thursday 25 January 2018, 11:00 at IPN, Salle A201 IPN-X (Séminaire commun de physique théorique des particules IPN-CPHT-X) hep-lat
Nicolas Garron ( Univ. of Liverpool ) The nucleon axial charge from Lattice QCD
Abstract: The axial coupling of the nucleon, gA, is a simple but fundamental quantity in particle physics. While gA is very well-measured experimentally, its theoretical prediction has been a long-standing puzzle: the lattice determinations being systematically below the experimental value. If we want to understand nuclear physics from first principle, it is crucial to solve this puzzle. I will present our recent computation performed with CalLat (California Lattice) based on a Feynman-Hellmann approach. Our result is in perfect agreement with the experimental value with an uncertainty of less than 2%. I will discuss the various sources of systematic errors and I will give the several ingredients that allow our determination to be significantly more precise than the previous lattice computations.

Thursday 25 January 2018, 11:45 at LPTHE, IMPMC, salle 401, tour 22-23, 4eme étage
( Beware, unusual location ! )
RENC-THEO (Rencontres Théoriciennes) hep-th
Piotr Tourkine ( CERN ) New duality symmetric theories from twisted strings
Abstract: Twistor strings have undergone a renewal of interest since the discovery of the Cachazo-He- Yuan formalism for scattering amplitude in field theory in 2013. These formulae deeply challenge the way we think about scattering amplitudes in quantum field theory and are neatly explained by the so-called ambitwistor string, a cousin of the old twistor string. The existence of these remarkable formalisms, which I shall present during the talk, cried for a connection to good old string theory. The answer to this question is now understood: it relies on counter-intuitive limits and crucially, the existence of a different quantization for string theory, which we called twisted strings. The first part of the talk will be concerned on making that connection to string theory clear. In the second part, I will report on recent results obtained with Eduardo Casali on the winding modes of these twisted strings. They give rise to new exotic target space theories, naively non unitary, but exhibiting features half way between string and field theory. In particular, they are T-duality symmetric.

Friday 26 January 2018, 10:00 at IPHT, Salle Claude Itzykson, Bât. 774
( https://courses.ipht.cnrs.fr/?q=fr/node/195 )
COURS (Cours) math.AG
Bertrand Eynard ( IPhT ) Riemann surfaces (3/5)
Abstract: Algebraic equations are widespread in mathematics and physics, and the geometry of their spaces of solutions can be complicated. In the case of an equation of two complex variables, the space of solutions is a Riemann surface. \par We will provide basic tools (going back to Riemann) for studying algebraic equations and describing the geometry of compact Riemann surfaces. \par We will consider a Riemann surface defined from the solution locus of a polynomial equation $P(x,y)=0$ in $\mathbb{C} \times \mathbb{C}$. We will study its topology and geometry, and learn how to integrate differential forms along closed contours. Then we will describe the moduli space of Riemann surfaces with a given topology: its dimension, topology, etc. \par We will introduce some of the many tools that have been invented since the time of Riemann for studying these objects. We will partly follow the Mumford Tata lectures, the Fay lectures, and the Farkas-Kra book. \\ \\ The plan is: \\ - Compact Riemann surfaces, charts, atlas, toplogy. Meromorphic functions and one-forms. Theorems on poles and residues. Newton's polygon. \\ - Integrals, periods, Abel map, Jacobian, divisors. Theta functions, prime form, fundamental form. Basis of cycles, homology and cohomology. \\ - Moduli spaces of Riemann surfaces. Deligne-Mumford compactification, Chern classes, tautological ring. Kontsevich integral and KdV hierarchy. \\ - If times permits: fiber bundles, Hitchin systems, link to integrable systems.
Attachments:
  • 2017-2018.pdf (4503344 bytes) OPEN
  • 2018_Eynard_0.pdf (4424243 bytes) OPEN

Friday 26 January 2018, 11:00 at LPTHE, Salle de cours du LPTMC (couloir 12-13, 5eme etage, salle 523)
( Attention: changement de salle )
SEM-LPTHE (Séminaire du LPTHE) cond-mat.stat-mech
André Neveu ( Laboratoire Charles Coulomb Montpellier ) A Bäcklund transformation for elliptic four-point conformal blocks
Abstract: In Liouville theory, we derive a partial differential equation for five-point correlation functions with one degenerate field $V_{-b/2}$. From it, one obtains explicit finite-dimensional integral representations in terms of elliptic theta-functions for a class of four-point conformal blocks for arbitrary intermediate dimension and generic value of the central charge. The conformal bootstrap can then be investigated analytically. Introducing a Bäcklund transformation on the solutions of the partial differential equation, one can reach a large extended set of external dimensions of these conformal blocks.

Monday 29 January 2018, 10:30 at IMPMC, Jussieu 23-22, 4e, salle 401 SEM-EXCEP (Séminaire exceptionel) physics
Sophie Lhenry ( Pôle égalité femmes-hommes, Université Paris-Diderot ) Les carrières en physique à l’épreuve du genre
Abstract: À partir de deux enquêtes sociologiques menées auprès de chercheur.e.s et d’enseignant.e.s-chercheur.e.s en STEM entre 2006 et 2016, nous aborderons les normes de réussite académique et leur aspect genré. Nous nous intéresserons particulièrement à l’impact de ces normes sur l’équilibre vie professionnelle/vie privée et sur les carrières des physiciens et physiciennes. Nous présenterons enfin les actions visant à favoriser les carrières des chercheur.e.s, expérimentées dans le cadre du projet européen TRIGGER et plus spécifiquement à l’université Paris Diderot à travers le Pôle Égalité Femmes-Hommes (PEFH).

Monday 29 January 2018, 13:30 at LPA, L363-365 LPA (Séminaire du laboratoire Pierre Aigrain) cond-mat
Claudia Felser ( Max Planck Institute for Chemical Physics of Solids, Dresden ) Topological Materials with liquid electrons
Abstract: Topology a mathematical concept became recently a hot topic in condensed matter physics and materials science. One important criteria for the identification of topological material is the band inversion and the crystal symmetry. In my talkI focus on new topological semimetals : Weyl semimetals. Binary phoshides are the ideal material class for a systematic study of Weyl physics. Weyl points, a new class of topological phases was also predicted in NbP, NbAs. TaP, MoP and WP2. In NbP micro-wires we have observed the chiral anomaly but NbP has served also as a model system for astrophysics : realizing the gravitational anomaly in NbP and the hydrodynamic flow of electrons in WP2. MoP and WP2 show exceptional properties such as high conductivity higher than copper, high mobilties and a high magneto-resistance effect. In magnetic materials, the Berry curvature measured via the classical anomalous Hall effect helps to identify interesting candidates for magnetic topological materials and devices.

Tuesday 30 January 2018, 13:30 at LPTM, Maison internationale de la recherche, Neuville-sur-Oise. SEM-EXCEP (Séminaire exceptionel) cond-mat.dis-nn
Roberto Livi ( Universita di Firenze, Italy ) Complex dynamics in neuromorphic circuits
Abstract: Neural population made of inhibitory and excitatory units exhibit complex collective dynamics when they are organized according to suitable circuits. In particular, amplification and synchronization mechanisms may emerge as purely noise driven effects: These results disclose new perspectives in the design of neuromorphic circuits performing specific tasks, like, signal categorization and detection.

Tuesday 30 January 2018, 14:00 at APC, 483 A - Malevitch APC-TH (Seminar of the theory group of APC) hep-th
Razvan Gurau ( CPHT - Ecole Polytechnique ) Invitation to Random Tensors
Abstract: Random matrices are ubiquitous in modern theoretical physics and provide insights on a wealth of phenomena, from the spectra of heavy nuclei to the theory of strong interactions or random two dimensional surfaces. The backbone of all the analytical results in matrix models is their 1/N expansion (where N is the size of the matrix). Despite early attempts in the '90, the generalization of this 1/N expansion to higher dimensional random tensor models has proven very challenging. This changed with the discovery of the 1/N expansion (originally for colored and subsequently for arbitrary invariant) tensor models in 2010. I this talk I will present a short introduction to the modern theory of random tensors and its connections to conformal field theory and random higher dimensional random geometry.

Tuesday 30 January 2018, 14:30 at IHES, Amphithéâtre Léon Motchane PT-IHES (Séminaire de physique théorique de l'IHES) hep-th
Pavel Saponov ( HSE & IHES ) Cayley-Hamilton Identity and Drinfeld-Sokolov Reduction in Quantum Algebras
Abstract: Different forms of the matrix Cayley-Hamilton identity in some quantum algebras will be presented. In particular, I plan consider the so-called braided Yangian -- some generalization of Drinfeld Yangian -- recently introduced in my joint work with D. Gurevich. A quantum counterpart of the Drinfeld-Sokolov reduction based on the Cayley-Hamilton identity will be discussed as well.

Tuesday 30 January 2018, 16:00 at IPHT, Salle Claude Itzykson, Bât. 774 IPHT-HEP (Séminaire de physique des particules et de cosmologie) hep-ph
Joan Elias Miro ( SISSA ) Towards a S-matrix bootstrap for unstable resonances
Abstract: The modern incarnation of the analytic S-matrix is a non-perturbative approach that consist in exploring the space of S-matrix elements consistent with unitarity, analyticity, crossing symmetry and some extra physical assumptions about the mass spectrum of particles. In this talk I will discuss my work in progress to extend the recent ideas of the S-matrix bootstrap to include unstable resonances. This extension is crucial in order to apply such program to realistic particle physics questions involving unstable bound states. The goal of the program I will discuss is to uncover the space of consistent S-matrices for Higgs-like bosons.

Thursday 1 February 2018, 11:00 at CPHT, Aile 0 SEM-CPHT (Séminaire du CPHT) hep-th
Markus Dierigl ( University Utrecht and University of Amsterdam ) Tensor-Matter transitions in F-theory
Abstract: F-theory models often exhibit singularities in codimension-two that cannot be resolved by a blow- up in the fiber alone. These points correlate with superconformal subsectors of the six-dimensional theory. However, they can be resolved by blow-ups in the base manifold leading to a change in the number of tensor multiplets. In this talk we will discuss transitions of models passing through such superconformal points and discuss the modification of the matter sector.

Thursday 1 February 2018, 11:30 at LPTENS, LPTENS Library STRINT (Strings, integrability and beyond) hep-th
Tba (ens/saclay Seminar) TBA

Thursday 1 February 2018, 13:30 at LPA, L363-365 LPA (Séminaire du laboratoire Pierre Aigrain) cond-mat
Marco Polini ( Instituto Italiano di Tecnologia, Genova & Scuola Normale Superiore, Pisa ) Topological and quantum plasmonics
Abstract: Plasmonics is a mature subfield of optoelectronics where light-matter interactions and propagating collective charge density excitations in a conductor are used to confine and steer electromagnetic energy in nanoscale devices. Progress in conventional metal-based plasmonics, however, has been hampered by substantial losses. Indeed, when electromagnetic fields are confined through the use of e.g. noble-metal plasmons, losses tend to be high and greatly limit the propagation distance of these collective modes. Substantial efforts have been recently made to increase the lifetime of these modes at room temperature, without decreasing the associated confining power. For example, one can utilize high-quality graphene sheets encapsulated in hexagonal boron nitride [1], where graphene plasmons scatter essentially only against the acoustic phonons of the two-dimensional (2D) carbon lattice, which are weakly coupled to the electronic degrees of freedom. Another possible pathway is to use plasmons in topologically-non-trivial materials. In the particular case of crystals displaying broken time-reversal symmetry (BTRS), the existence of unidirectional propagating modes akin to the ultra-long-lived [2] topological [3] edge magnetoplasmons that occur in 2D electron systems in the quantum Hall regime is expected. Technologically, it would be extremely useful to use materials where BTRS occurs without the aid of an external magnetic field. Natural candidates among topological materials with BTRS are recently discovered Weyl semimetals (WSMs) [4-7]. These are semimetals with protected linear band crossings in the Brillouin zone, which act as power-law-decaying sources of Berry curvature. Some of these compounds do display intrinsic BTRS [8] and, at the same time, have intriguing topological surface states called “Fermi arcs” (FAs). In this talk, I will present a fully quantum-mechanical theory of WSM FA plasmons [9]. The present derivation focuses on the simplest microscopic model Hamiltonian of a (type-I) WSM with BTRS [4-7] and is based on linear response theory [10] and the random phase approximation (RPA) [10]. We focus on the electrostatic regime, where the plasmon wave number is much larger than the photon one, enabling great concentration of electromagnetic energy. I will discuss how quantum non-local effects are crucial to understand WSM FA plasmon physics. Since the FA wavefunctions are in strong spatial overlap with a bulk of gapless excitations, FA plasmons are susceptible to Landau damping even at zero temperature and deep in the long-wavelength limit. Our theory fully quantifies this intrinsic dissipation mechanism, which is dominated by processes whereby FA plasmons decay by emitting electron-hole pairs in the bulk, and puts strict theoretical bounds on the observability of certain angular portions of the highly-anisotropic FA plasmon dispersion. Finally, if time allows, I will also discuss recent progress in understanding quantum non-local effects in graphene plasmonics [11]. In this case, we have used a combination of graphene plasmons and engineered dielectric-metallic environments, to probe the local shape of density correlations in the graphene electron liquid. Near-field imaging experiments in the Terahertz (THz) spectral range have revealed a parameter-free match with the full theoretical quantum description of the massless Dirac electron gas, in which we have identified three types of quantum effects as keys to understanding the response of graphene to short-ranged THz electric fields. The first type is of single-particle nature and is related to shape deformations of the Fermi surface during a plasmon oscillation. The second and third types are a many-body effect controlled by the inertia and compressibility of the interacting electron liquid in graphene. Our work paves the way for accessing the full non-local conductivity tensor of electron liquids in 2D materials and surface states of WSMs and topological insulators. References [1] A. Woessner, M.B. Lundeberg, Y. Gao, A. Principi, P. Alonso-González, M. Carrega, K. Watanabe, T. Taniguchi, G. Vignale, M. Polini, J. Hone, R. Hillenbrand, and F.H.L. Koppens, Nature Mater. 14, 421 (2015). [2] N. Kumada, P. Roulleau, B. Roche, M. Hashisaka, H. Hibino, I. Petković, and D.C. Glattli, Phys. Rev. Lett. 113, 266601 (2014). [3] D. Jin, L. Lu, Z. Wang, C. Fang, J.D. Joannopoulos, M. Soljačić, L. Fu, and N.X. Fang, Nature Commun. 7, 13486 (2016). [4] P. Hosur and X. Qi, C.R. Physique 14, 857 (2013). [5] M.Z. Hasan, S.-Y. Xu, I. Belopolski, and S.-M. Huang, Annu. Rev. Condens. Matter Phys. 8, 289 (2017). [6] B. Yan and C. Felser, Annu. Rev. Condens. Matter Phys. 8, 337 (2017). [7] A.A. Burkov, Annu. Rev. Condens. Matter Phys. 9, 359 (2018). [8] C. Shekhar, A.K. Nayak, S. Singh, N. Kumar, S.-C. Wu, Y. Zhang, A.C. Komarek, E. Kampert, Y. Skourski, J. Wosnitza, W. Schnelle, A. McCollam, U. Zeitler, J. Kubler, S.S.P. Parkin, B. Yan, and C. Felser, arXiv:1604.01641. [9] G.M. Andolina, F.M.D. Pellegrino, F.H.L. Koppens, and M. Polini, arXiv:1706.06200. [10] D. Pines and P. Noziéres, The Theory of Quantum Liquids (W.A. Benjamin, Inc., New York, 1966). [11] M.B. Lundeberg, Y. Gao, R. Asgari, C. Tan, B. Van Duppen, M. Autore, P. Alonso-Gonzalez, A. Woessner, K. Watanabe, T. Taniguchi, R. Hillenbrand, J. Hone, M. Polini, and F.H.L. Koppens, Science 357, 187 (2017).

Thursday 1 February 2018, 14:00 at LPTM, 4.13 St Martin II SEM-LPTM-UCP (Seminaires du LPTM , Universite de Cergy Pontoise) cond-mat
Pierre Fromholz ( LPTM UCP Cergy Pontoise ) TBA
Abstract: TBA

Thursday 1 February 2018, 14:30 at LPTENS, LPTENS Library STRINT (Strings, integrability and beyond) hep-th
Tba (ens/saclay Seminar) TBA

Friday 2 February 2018, 10:00 at IPHT, Salle Claude Itzykson, Bât. 774
( https://courses.ipht.cnrs.fr/?q=fr/node/195 )
COURS (Cours) math.AG
Bertrand Eynard ( IPhT ) Riemann surfaces (4/5)
Abstract: Algebraic equations are widespread in mathematics and physics, and the geometry of their spaces of solutions can be complicated. In the case of an equation of two complex variables, the space of solutions is a Riemann surface. \par We will provide basic tools (going back to Riemann) for studying algebraic equations and describing the geometry of compact Riemann surfaces. \par We will consider a Riemann surface defined from the solution locus of a polynomial equation $P(x,y)=0$ in $\mathbb{C} \times \mathbb{C}$. We will study its topology and geometry, and learn how to integrate differential forms along closed contours. Then we will describe the moduli space of Riemann surfaces with a given topology: its dimension, topology, etc. \par We will introduce some of the many tools that have been invented since the time of Riemann for studying these objects. We will partly follow the Mumford Tata lectures, the Fay lectures, and the Farkas-Kra book. \\ \\ The plan is: \\ - Compact Riemann surfaces, charts, atlas, toplogy. Meromorphic functions and one-forms. Theorems on poles and residues. Newton's polygon. \\ - Integrals, periods, Abel map, Jacobian, divisors. Theta functions, prime form, fundamental form. Basis of cycles, homology and cohomology. \\ - Moduli spaces of Riemann surfaces. Deligne-Mumford compactification, Chern classes, tautological ring. Kontsevich integral and KdV hierarchy. \\ - If times permits: fiber bundles, Hitchin systems, link to integrable systems.
Attachments:
  • 2017-2018.pdf (4503344 bytes) OPEN
  • 2018_Eynard_0.pdf (4424243 bytes) OPEN

Friday 2 February 2018, 11:00 at LPTHE, Bibliothèque SEM-LPTHE (Séminaire du LPTHE) cond-mat.stat-mech
Lev Ioffe ( LPTHE ) Non-ergodicity in many body systems and disordered random graphs; application to the phase diagram of Josephson junction chain
Abstract: At very high disorder a generic closed quantum systems becomes completely localized. I argue that this (may body) localization is preempted by a wide regime of non-ergodic behavior that displays a number of unusual properties. A good system to study these effects are Josephson junction arrays in a somewhat unusual regime. The toy model of disordered many body systems that capture the physics of many body systems is provided by random regular graphs. I will sketch a simplified analytical theory of the non-ergodic phase in this models, compare the results with the direct numerical simulations and summarize the conclusions relevant for physical many body systems.

Friday 2 February 2018, 11:30 at SAMM, C20.13 (Centre PMF, 90 rue de Tolbaic, Paris 13e) SAMM (Statistics, Analysis, Multidisciplinary Modeling) cond-mat|cond-mat.stat-mech|math.CO|math.PR
Dmitry Zaporozhets ( Steklov St Petersbourg ) On random simplexes

Monday 5 February 2018, 11:00 at IPHT, Salle Claude Itzykson, Bât. 774 IPHT-PHM (Séminaire de physique mathématique) math-ph
Sanjay Ramassamy ( ENS, Lyon ) Miquel dynamics on circle patterns
Abstract: Circle patterns are one of the ways to uniformize graphs on surfaces, by embedding them in such a way that every face admits a circumcircle. In this talk I will describe a discrete-time dynamical system on circle patterns with the combinatorics of the square grid, called Miquel dynamics. It is based on the classical Miquel's six circles theorem. I will present some properties of this dynamics which suggest its integrability. \\ \\ Partly joint work with Alexey Glutsyuk (CNRS, Ecole normale superieure de Lyon / Higher School of Economics).

Monday 5 February 2018, 13:30 at LPA, L363-365 LPA (Séminaire du laboratoire Pierre Aigrain) cond-mat
Alexandru Petrescu ( Department of Electrical Engineering, Princeton University ) Fluxon-Based Quantum Simulation in circuit QED
Abstract: Long-lived fluxon excitations can be trapped inside a superinductor ring, which can be realized with a long array of Josephson junctions, one of which offers the input/ output path for the magnetic flux [1]. The superinductor ring can be separated into smaller loops by a periodic sequence of Josephson junctions in the quantum regime, thereby allowing fluxons to tunnel between neighboring loops. This model is dual to that of two-leg ladder bosons, which have a rich phase diagram depending on flux and density [2]. By tuning the Josephson coupling, and implicitly the tunneling probability amplitude of fluxons, a wide class of 1D tight-binding lattice models may be implemented and populated with a stable number of fluxons. In this context, fluxons are lattice bosons with repulsive interactions. We illustrate this quantum simulation platform by discussing the Su-Schrieffer-Heeger model in the 1-fluxon subspace, which hosts a symmetry protected topological phase with fractionally charged bound states at the edges [3]. This pair of localized edge states could be used to implement a superconducting qubit increasingly decoupled from decoherence mechanisms. [1] N. A. Masluk, I. M. Pop, A. Kamal, Z. K. Minev, and M. H. Devoret, Phys. Rev. Lett. 109, 137002 (2012). [2] E. Orignac and T. Giamarchi, Phys. Rev. B 64, 144515 (2001); A. Petrescu and K. Le Hur, Phys. Rev. Lett. 111, 150601 (2013); M. Piraud, F. Heidrich-Meisner, I. P. McCulloch, S. Greschner, T. Vekua, and U. Schollwllwock, Phys. Rev. B 91, 140406 (2015); A. Petrescu, M. Piraud, G. Roux, I. P. McCulloch, and K. Le Hur, Phys. Rev. B 96, 014524 (2017). [3] R. Jackiw and C. Rebbi, Phys. Rev. D 13, 3398 (1976); W. P. Su, J. R. Schrie-er, and A. J. Heeger, Phys. Rev. Lett. 42, 1698 (1979).

Tuesday 6 February 2018, 10:00 at IHES, Amphi. Léon Motchane MATH-IHES (TBA) hep-th
Lucian M. Ionescu ( Illinois State Univ. & IHES ) Periods: « Variations sur un thème de Kontsevich »
Abstract: Periods, numerical as algebraic integrals, and abstract, associated to de Rham comparison isomorphism, are fundamental in Physics and Mathematics. ... Why are they so much related!? Various considerations regarding their geometric and dynamic interpretation will be provided, together with thoughts requiring further readings and study.

Tuesday 6 February 2018, 11:30 at LPTENS, LPTENS library STR-LPT-ENS-HE (Séminaire commun LPTENS/LPTHE) hep-th
Blagoje Oblak ( ETH ) Berry Phases of Boundary Gravitons
Abstract: This talk is devoted to Berry phases that appear in unitary representations of asymptotic symmetry groups in general relativity. These phases arise when a coherent state is acted upon by symmetry transformations that trace a closed path in the group manifold, and they can be evaluated exactly even when the group is infinite-dimensional. We apply these ideas to the Virasoro and BMS groups; seeing their representations as particles dressed with boundary gravitons, the associated Berry phases generalize Thomas precession and provide, in principle, observable signatures of asymptotic symmetries.

Tuesday 6 February 2018, 16:00 at IPHT, Salle Claude Itzykson, Bât. 774 IPHT-HEP (Séminaire de physique des particules et de cosmologie) hep-ph
Marco Ruggieri ( School of Nuclear Science and Technology, Lanzhou University ) Gluon fields in high energy proton-proton collisions
Abstract: The initial stage of inelastic high energy nuclear collisions is known as the Glasma, namely a configuration of strong chromo-electric and chromo-magnetic fields which develop along the flight direction of the two colliding nuclei; the evolution of these fields eventually leads to the formation of the quark-gluon plasma. In this seminar I focus on the Glasma that can be produced in high energy proton-proton collisions. The main goals are the study of isotropization, of gauge invariant correlation functions that allow us to understand the building up of color domains and the string breaking of the Glasma starting from the color strings, and of the distribution of the topological charge density which might be relevant for the chiral magnetic effect.

Tuesday 6 February 2018, 17:15 at DPT-PHYS-ENS, room Jean Jaurès (29 rue d'Ulm) SEM-PHYS-ENS (Colloquium du Département de Physique de l'ENS) cond-mat.mes-hall
Jacqueline Bloch ( Center for Nanoscience and Nanotechnology, Marcoussis ) Fluids of light in semiconductor lattice
Abstract: When confining photons in semiconductor lattices, it is possible deeply modifying their physical properties. Photons can behave as finite or even infinite mass particles, photons can propagate along edge states without back scattering, photons can become superfluid, photons can behave as interacting particles. These are just a few examples of properties that can be imprinted into fluids of light in semiconductor lattices. Such manipulation of light present not only potential for applications in photonics, but great promise for fundamental studies. One can invent artificial media with very exotic physical properties at the single particle level or even more interestingly when many body interactions are considered. During the talk, I will illustrate the variety of physical systems we can emulate with fluids of light by presenting a few recent experiments. Perspectives in terms of quantum simulation will be discussed.

Thursday 8 February 2018, 11:00 at LPTHE, bibliothèque SEM-DARBOUX (Séminaire Darboux - physique théorique et mathématiques) math|math.MP
Emmanuel Letellier ( IMJ-PRG ) TBA

Thursday 8 February 2018, 14:00 at LPTM, 4.13 St Martin II SEM-LPTM-UCP (Seminaires du LPTM , Universite de Cergy Pontoise) physics.optics
Pierre Elie Larre ( LPTM UCP Cergy Pontoise ) Quantum simulating many-body phenomena with propagating light
Abstract: We consider the propagation of a quantum light field in a cavityless nonlinear medium. In this all-optical platform, the space propagation of the field's envelope may be mapped onto the time evolution of a quantum fluid of interacting photons. The resulting many-body quantum system constitutes a particular class of quantum fluids of light and presently attracts a growing interest as a powerflul tool for quantum simulation. I will present recent theoretical and experimental progresses in this rapidly emerging research field, including investigations on superfluidity, elementary excitations, disorder, quantum quenches, prethermalization, thermalization, and Bose-Einstein condensation.

Thursday 8 February 2018, 16:00 at LPT, 114 LPT-PTH (Particle Theory Seminar of LPT Orsay) hep-ph
Martin Gonzalez-Alonso Precision vs. energy in the Standard Model EFT
Abstract: I will introduce the Standard Model Effective Field Theory (SMEFT) as a general framework to analyse experimental searches. I will discuss the interplay of precision measurements in low- and medium-energy facilities with high-energy searches at the LHC, using the SMEFT as theoretical framework. Specific examples will be discussed, including nuclear/atomic probes, LEP searches or flavour transitions. In each case, the synergy with LHC searches will be discussed.

Thursday 8 February 2018, 16:30 at INSP, 22-23 3ème étage pièce 317 SEM-INSP (Séminaire général de l'INSP) physics|physics.ao-ph|physics.gen-ph|physics.med-ph|physics.soc-ph
Bernard Clerjaud ( Institut des NanoSciences de Paris ) Quelques aspects des particules fines
Abstract: Cet exposé se concentrera sur les particules de diamètres aérodynamiques inférieurs à 10 $\mu$m. La dynamique de ces particules sera décrite et illustrée par le nuage de cendres volcaniques ayant recouvert l’Europe en 2010 suite à l’éruption du volcan Eyjafjallajökull. Dans une deuxième partie, on verra que les particules fines se retrouvent dans la chaine alimentaire et comment on peut retracer l’histoire des explosions atmosphériques d’armes nucléaires et des accidents dans les centrales nucléaires à travers l’analyse de la radioactivité des millésimes des vins. La troisième partie sera consacrée à la pollution de l’air par les particules fines à « l’air libre » et dans un milieu clos : le métro parisien ; l’origine des polluants sera discutée. La dernière partie de l’exposé sera consacrée à l’effet des particules fines inhalées sur les êtres humains et discutera l’origine des particules « tueuses ».

seminars from series at institute
in subject with field matching

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