SEMPARIS : Le serveur des séminaires parisiens

Le serveur de séminaires SEMPARIS accueille toutes les annonces de séminaires de la région parisienne, dans tous les domaines de la physique et des mathématiques. Il vous permet aussi de recevoir par courrier électronique la sélection de votre choix. Enfin, il a vocation à devenir une base de connaissances, grâce à l'archivage des présentations au format PDF ou Powerpoint. [ Plus d'informations ]

Séminaires aujourd'hui, Mardi 9 Fevrier 2010

Mardi 9 Fevrier 2010, 11:00 à LPT, Salle de cosmologie (salle 110) 1er étage du LPT
( Séminaire de cosmologie ) SEM-LPT (Séminaire de Physique des Particules du LPT) gr-qc

Camille Bonvin ( CEA ) Full-sky gravitational lensing: new relativistic effects in convergence and second-order shear

Abstract: Future lensing surveys aim at observing almost the whole sky. They will measure lensing correlations at very large scales. At those scales, new relativistic effects will come into play and open the way to new type of studies. In this talk, I will present a fully relativistic calculation of weak gravitational lensing up to second order in the gravitational potential. First, I will show that the convergence part of weak lensing contains new effects that are neglected at small scales. I will show that one of these contributions, generated by peculiar velocities of galaxies, becomes important at large scales. At small redshifts, it has an observable impact on the convergence power spectrum. Then I will present a calculation of the shear part of weak lensing up to second order. I will show that at large scales various non-linear couplings appear that can potentially provide new tests of gravity.

Mardi 9 Fevrier 2010, 14:00 à APC, 454A - Klee APC-TH (Seminar of the theory group of APC) gr-qc

Alexandre Le Tiec ( IAP (Paris) ) Comparing and combining post-Newtonian methods with black hole perturbations

Abstract: There are two main approximation schemes to model the dynamics of coalescing compact binaries, and the associated generation of gravitational radiation: (i) the post-Newtonian formalism, well suited to describe the inspiraling phase of arbitrary mass ratio compact binaries in the slow motion and weak field regime, and (ii) black hole perturbation theory, which gives an accurate description of the ringdown phase, or can be applied to extreme mass ratio binaries, even in the strong field regime. We shall first present a recent comparison of these two formalisms in their common domain of validity: the slow motion regime of an extreme mass ratio black hole binary. Second we will show how the close-limit approximation with post-Newtonian initial conditions can shed light on the gravitational recoil accumulated during the ringdown phase of coalescing binary black holes.

les séminaires dans la série
à l' institut dans le domaine
et dont le champ comprend la séquence

[ Affiche Postscript

| Affiche PDF

| Fil RSS | Format ICal

]

Vous êtes invité à souscrire aux listes de distribution SEMPARIS afin de recevoir les annonces par courrier électronique.

[ Site public ] [ Site personnel ] [ Archive NEW ] [ Aide ] [ Contact ] [ English version ]

Mardi 9 Fevrier 2010, 11:00 à LPT, Salle de cosmologie (salle 110) 1er étage du LPT ( Séminaire de cosmologie )	SEM-LPT (Séminaire de Physique des Particules du LPT)	gr-qc
Camille Bonvin ( CEA )	Full-sky gravitational lensing: new relativistic effects in convergence and second-order shear
Abstract:	Future lensing surveys aim at observing almost the whole sky. They will measure lensing correlations at very large scales. At those scales, new relativistic effects will come into play and open the way to new type of studies. In this talk, I will present a fully relativistic calculation of weak gravitational lensing up to second order in the gravitational potential. First, I will show that the convergence part of weak lensing contains new effects that are neglected at small scales. I will show that one of these contributions, generated by peculiar velocities of galaxies, becomes important at large scales. At small redshifts, it has an observable impact on the convergence power spectrum. Then I will present a calculation of the shear part of weak lensing up to second order. I will show that at large scales various non-linear couplings appear that can potentially provide new tests of gravity.

Mardi 9 Fevrier 2010, 14:00 à APC, 454A - Klee	APC-TH (Seminar of the theory group of APC)	gr-qc
Alexandre Le Tiec ( IAP (Paris) )	Comparing and combining post-Newtonian methods with black hole perturbations
Abstract:	There are two main approximation schemes to model the dynamics of coalescing compact binaries, and the associated generation of gravitational radiation: (i) the post-Newtonian formalism, well suited to describe the inspiraling phase of arbitrary mass ratio compact binaries in the slow motion and weak field regime, and (ii) black hole perturbation theory, which gives an accurate description of the ringdown phase, or can be applied to extreme mass ratio binaries, even in the strong field regime. We shall first present a recent comparison of these two formalisms in their common domain of validity: the slow motion regime of an extreme mass ratio black hole binary. Second we will show how the close-limit approximation with post-Newtonian initial conditions can shed light on the gravitational recoil accumulated during the ringdown phase of coalescing binary black holes.