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Seminar at the

Laboratoire Jacques-Louis Lions

Université Pierre et Marie Curie, Paris

Organizers

 Philippe G. LeFloch (Paris)

 Jacques Smulevici (Orsay)

Jérémie Szeftel (Paris)


 This Fall: October 10, November 21, and December 12, 2016


 

Monday October 10, 2016

room 15/25-104

 

 14h Peter Hintz (Berkeley)

Nonlinear stability of Kerr-de Sitter black holes

Abstract. In joint work with András Vasy, we recently established the stability of the Kerr-de Sitter family of black holes as solutions of the initial value problem for the Einstein vacuum equations with positive cosmological constant, for small angular momenta but without any symmetry assumptions on the initial data. I will explain the general framework which enables us to deal systematically with the diffeomorphism invariance of Einstein’s equations, and thus how our solution scheme finds a suitable (wave map type) gauge within a carefully chosen finite-dimensional family of gauges; I will also address the issue of finding the mass and the angular momentum of the final black hole.

 15h30 Stefan Czimek (Paris)

An extension procedure for the constraint equations

Abstract. In this talk we present a new extension procedure for the maximal constraint equations of general relativity, motivated by applications to the Cauchy problem. Given a small solution on the unit ball, we can extend it to an asymptotically flat global solution. The main features are that our extension procedure does not need a gluing region, preserves regularity and works in weak regularity. For the proof, we use new methods to solve the prescribed divergence equation for the second fundamental form and the prescribed scalar curvature equation for the metric. We use the under-determinedness of the constraint equations to conserve regularity.

 


 

Monday November 21, 2016

room 15/16-413

 

14h The-Cang Nguyen (Paris)

Progress and recent results for the conformal equations

Abstract. The presentation will be divided into two parts. First, I will introduce the conformal equations and present recent results for these equations as well as questions arising naturally. In a second part, I will talk about the “half-continuity method” and explain how to use this method for giving answers to the questions posed in the first part.

15h30 Volker Schlue (Paris)

On the nonlinear stability of expanding black hole cosmologies

 


 

Monday December 12, 2016

room 15/25-102

 

14h Michał Wrochna (Grenoble)

The quantum stress-energy tensor and its intricate relationship with spacetime geometry

Abstract. It is widely believed that at low energies, quantum gravity should yield an effective theory described by Einstein equations with a stress-energy tensor made of averaged fluctuations of quantum fields. The construction of that stress-energy tensor is however very problematic and its intricate dependence on spacetime geometry results in highly non-linear equations that possess no qualitative theory to date. In this talk I will review this problem as a motivation for improving the construction of linear Klein-Gordon quantum fields, and discuss recent progress that allows for a better control of the dependence on the spacetime metric (partly based on joint work with Christian Gérard).

15h30 Guillaume Idelon-Riton (Regensburg)

Some results about the scattering theory for the massive Dirac fields in the Schwarzschild-Anti-de Sitter space-time

Abstract.  I will first give a brief presentation of the Schwarzschild-Anti-de Sitter spacetime and of some of its geometrical properties that will concern us. Then I will present the massive Dirac equation in this space-time and first study the Cauchy problem which is not completely obvious since our spacetime is not globally hyperbolic. I will then give a result concerning the asymptotic completeness for these fields. By means of a Mourre estimate, it is possible to obtain that the minimal velocity for these fields is 1. I will then show that our dynamics behaves in asymptotic regions like a transport at unit speed in the direction of the black hole. In a third part, I will study the local energy decay for these fields. First, using the existence of exponentially accurate quasi-modes, I will show a logarithmic lower bound on the local energy decay which is in accordance with the results of G. Holzegel and J. Smulevici in the Kerr-Anti-de Sitter spacetime for the Klein-Gordon fields. In order to obtain an upper bound, I will prove the existence of resonances and give some tools in order to localize them.

 

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Workshop 2016

“Modeling and Computation of Shocks and Interfaces”

Laboratoire Jacques-Louis Lions

Université Pierre et Marie Curie, Paris

Organizers

 Philippe G. LeFloch (Paris)

 Charalambos Makridakis  (Brighton)

Supported by the ModCompShock ITN project

and a project PICS CNRS


 Dec. 6 around 1:30pm to Dec. 8 around 1pm


Main speakers

Remi Abgrall (Zurich)

Benjamin Boutin (Rennes)

Christophe Chalons (Versailles)

Sergey Gavrilyuk (Marseille)

Charalambos Makridakis (Brighton)

Pierangelo Marcati (L’Aquila)

Siddhartha Mishra (Zurich)

Carlos Pares (Malaga)

Nils Risebro (Oslo)

Giovanni Russo (Catania)

Lev Truskinovsky (Palaiseau)

 


Titles of the lectures

Remi Abgrall

Benjamin Boutin Numerical boundary layers for linear hyperbolic IBVP and semigroup estimate

Christophe Chalons On the computation of non conservative products and cell averages in finite volume methods

Makridakis Charalambos  Energy/entropy consistent computational methods

Sergey Gavrilyuk Shock-droplet interaction via a new hyperbolic phase field model

Pierangelo Marcati Splash singularities for incompressible viscoelatic fluids 

Siddhartha Mishra Statistical solutions of systems of conservation laws

Carlos Pares Entropy stable schemes for degenerate convection-diffusion equations

Nils Risebro  Numerical methods for scalar conservation laws with a stochastically driven flux

Giovanni Russo Shock capturing schemes for all Mach number flow in gas dynamics

Lev Truskinovsky Solitary waves in the FPU lattice: from quasi-continuum to anti-continuum limit


Schedule of the workshop

Tuesday afternoon

2pm-2:45pm: C. Makridakis

2:45-3:30pm: C. Pares

3:30pm: coffee break

4pm-4:45pm G. Russo

Wednesday morning

10am-10:45am: S. Gavrilyuk

10:45am: coffee break

11:15am: C. Chalons

Noon: lunch buffet

Wednesday afternoon

2pm-2:45pm R. Abgrall

2:45pm-3:30pm S. Mishra

3:30am coffee break

4pm L. Truskinovsky

Thursday morning

9:30am-10:15am N. Risebro

10:15am coffee break

10:45am B. Boutin

11:30am P. Marcati

12:15 lunch buffet (end of the workshop)



Participants to the workshop


Other practical informations

The workshop will take place in the main lecture room 309 of the Laboratoire Jacques-Louis Lions, Université Pierre et Marie Curie, which is located in the building 15-16.

Address: 4 Place Jussieu, 75258 Paris. Subway station: Jussieu.

List of hotels in the vicinity of the university

Philippe LeFloch, DIRECTOR OF RESEARCH AT CNRS Email address: pglefloch [at] gmail.com

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