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Upcoming Seminars  
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Tuesday 20 August 2019, 13:30 at
LPT,
114 ( This is the first of a series of lectures on neutron stars. This one will be quite elementary, subsequent lectures will be more advanced. )  LPTPTH (Particle Theory Seminar of LPT Orsay)  nuclth 



Abstract:  In this first lecture, I will talk about the basics of neutron stars. I will first give a historical review on neutron stars, such as on the first theoretical prediction of neutron stars, the first neutron star model, the discovery of pulsars, and their identification to neutron stars. Then, I will discuss the properties of neutron stars and the observational confirmation of these properties. 
Tuesday 3 September 2019, 11:00 at IPHT, Salle Claude Itzykson, Bât. 774  IPHTGEN (Séminaire général du SPhT)  physics 



Abstract:  By definition the choreography (dancing curve) is a closed trajectory on which $n$ classical bodies move chasing each other without collisions. The first choreography (the Remarkable Figure Eight) at zero angular momentum was discovered unexpectedly by C Moore (Santa Fe Institute) at 1993 for 3 equal masses in $R^3$ Newtonian gravity numerically. At the moment about 6,000 choreographies in $R^3$ Newtonian gravity are found, all numerically for different $n > 2$. A number of 3body choreographies is known in $R^2$ Newtonian gravity, for LennardJones potential (hence, relevant for molecular physics), and for some other potentials, again numerically; it might be proved their existence for quarkonia potential. \par Does exist (non)Newtonian gravity for which dancing curve is known analytically?  Yes, a single example is known  it is algebraic lemniscate by Jacob Bernoulli (1694)  and it will be a concrete example of the talk. Astonishingly, $R^3$ Newtonian Figure Eight coincides with algebraic lemniscate with $\chi^2$ deviation $\sim 10^{7}$. Both choreographies admit any odd numbers of bodies on them. Both 3body choreographies define maximally superintegrable trajectory with 7 constants of motion. \par Talk will be accompanied by numerous animations. 
Wednesday 4 September 2019, 14:15 at IPHT, Salle Claude Itzykson, Bât. 774  IPHTMAT (Séminaire de matrices, cordes et géométries aléatoires)  hepth 



Abstract:  (TBA) 
Friday 6 September 2019, 14:00 at LPTHE, library  LPTHEPPH (Particle Physics at LPTHE)  hepph 


Tuesday 10 September 2019, 11:00 at LPTENS, LPTENS library  STRINT (Strings, integrability and beyond)  hepth 


Friday 13 September 2019, 11:00 at LPTHE, Bibliothèque  SEMLPTHE (Séminaire du LPTHE)  condmat.statmechhepthmathmathph 



Abstract:  In this seminar, I will discuss integrable systems called affine Gaudin models and their application to the study of integrable sigma models. As an introductory example, I will first discuss a simpler class of Gaudin models, the finite ones, and their relation with integrable spin chains and mechanical systems. I will then explain how to use affine Gaudin models to construct new integrable classical sigma models, by coupling together an arbitrary number of principal chiral models with WessZumino terms. 
Monday 16 September 2019, 10:45 at LPTMC, Jussieu, tower 1312, room 523  SEMLPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)  condmat.meshall 



Abstract:  We identify the persistence probability for the spin located at the origin of a halfspace magnetized GlauberIsing chain as a Fredholm Pfaffian gap probability generating function with a sechkernel. This is then recast as a taufunction for a certain Painlevé VI transcendent  a sort of exact Kramers' formula for the associated explicitely timedependent Hamiltonian  where the persistence exponent emerges as an asymptotic decay rate. By a known yet remarkable correspondence that relates Painlevé equations to Bonnet surfaces, the persistence probability has also a geometric meaning à la GaussBonnet in terms of the intrinsic curvature of the underlying surface. Since the same sechkernel with an underlying Pfaffian structure shows up in a variety of Gaussian firstpassage problems, our Painlevé VI characterization appears as a universal probability distribution akin to the famous Painlevé II TracyWidom laws. Its tail behavior in the magnetizationsymmetric case allows in particular to recover the exact value 3/16 for the persistence exponent of a 2d diffusing random field, as found very recently by Poplavskyi and Schehr (arXiv:1806.11275). Due to its topological origin, this value should constitute the superuniversal persistence exponent for the coarsening of a nonconserved scalar order parameter in two space dimensions. 
Monday 16 September 2019, 14:00 at LPNHE, Amphi Charpak  LPNHE (Séminaires du LPNHE)  hepex 


Tuesday 17 September 2019, 11:30 at LPTHE, LPTHE library  STRLPTENSHE (Séminaire commun LPTENS/LPTHE)  hepth 



Abstract:  (based on 1905.05207 ) 
Wednesday 18 September 2019, 13:45 at DPTPHYSENS, Sorbonne Université – 4, place Jussieu – 75005 Paris, Room : TBC  SEMPHYSENS (Colloquium du Département de Physique de l'ENS)  quantph 



Abstract:  The dream of the quantum engineer is to have an “arbitrary waveform generator” for designing quantum states and Hamiltonians. Motivated by this vision, I will report on advances in optical control of longrange interactions among cold atoms. By coupling atoms to light in an optical resonator, we induce tunable nonlocal spinspin interactions, characterizing the resulting dynamics by realspace imaging. Notably, in a spin1 system, we observe photonmediated spin mixing, a new mechanism for producing correlated atom pairs. In a separate platform, we employ Rydberg dressing to induce Ising interactions in a dilute gas of cesium atoms in their hyperfine clock states, enabling the realization of a Floquet transversefield Ising model. I will discuss prospects in quantum simulation and quantum metrology promised by the versatility of optical control. [1] Ar39 dating with small samples provides new key constraints on ocean ventilation, Nature Comm. 9, 5046 (2018).[2] Observation of universal dynamics in a spinor Bose gas far from equilibrium, Nature 563, 217 (2018). 
Monday 23 September 2019, 10:45 at LPTMC, Jussieu, tower 1312, room 523  SEMLPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)  condmat.meshall 


Thursday 26 September 2019, 11:00 at LPTHE, bibliothèque du LPTHE, tour 1314, 4eme étage  SEMDARBOUX (Séminaire Darboux  physique théorique et mathématiques)  math.AG 


Monday 30 September 2019, 10:45 at LPTMC, Jussieu, tower 1312, room 523  SEMLPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)  condmat.meshall 


Wednesday 2 October 2019, 14:15 at IPHT, Salle Claude Itzykson, Bât. 774  IPHTMAT (Séminaire de matrices, cordes et géométries aléatoires)  hepth 


Monday 7 October 2019, 11:00 at IPHT, Salle Claude Itzykson, Bât. 774  IPHTPHM (Séminaire de physique mathématique)  mathph 



Abstract:  The Raise and Peel model is a stochastic model of fluctuating interface with nonlocal avalanche dynamics. Its dynamical rules stem from the Â structure of a specific representation of the TemperleyLieb algebra, and its stochastic generator can be represented by the Hamiltonian of the XXZ Heisenberg quantum spin chain with twisted boundary conditions.Â We describe the Â recent progressÂ in description of the statistics of the avalanches in the model. We focus on the large deviations of two avalanche currents in the thermodynamic limit,Â which reveal a Â phase transition in the behaviour of one current conditioned to Â atypical values of another one. We Â also describe a proof of the Â laws ofÂ large numbers for the two currents at arbitrary finite lattices, which in addition proves two earlier conjectures on the structure of the stationary state of the model. The technique is based on the analysis of the largest eigenvalue of the deformed stochastic generator using the Bethe ansatz and Baxter 
Thursday 10 October 2019, 11:00 at LPTHE, bibliothèque du LPTHE, tour 1314, 4eme étage  SEMDARBOUX (Séminaire Darboux  physique théorique et mathématiques)  math.NT 


Tuesday 22 October 2019, 11:30 at LPTENS, LPTENS library  STRLPTENSHE (Séminaire commun LPTENS/LPTHE)  hepth 


Monday 25 November 2019, 10:45 at LPTMC, Jussieu, tower 1312, room 523  SEMLPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)  condmat.meshall 


Monday 9 December 2019, 10:45 at LPTMC, Jussieu, tower 1312, room 523  SEMLPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée)  condmat.meshall 


Thursday 12 December 2019, 11:00 at LPTHE, bibliothèque du LPTHE, tour 1314, 4eme étage  SEMDARBOUX (Séminaire Darboux  physique théorique et mathématiques)  math.AG 



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