SÉMINAIRE DU GRECO
"A fully-constrained formulation of Einstein equations: setup and numerical implementation" |
||

J. Novak |
||

Within the 3+1 approach, Einstein equations separate into six evolution equations and four constraints. In this seminar, I shall introduce the fully-constrained formalism of Einstein equations, developed by Bonazzola et al. (2004) and its recent improvement by Cordero et al. (2009). This formalism is motivated by its capacity in controlling the violation of the constraints, thus leading to a very accurate integration scheme, when numerically solving the Einstein equations in astrophysical scenarios as the evolution of a neutron star or the supernova core-collapse. In the second part of this talk, I shall give some details about the computational techniques used to solve the evolution equations within this formalism, while ensuring the Dirac gauge. The problem is to solve a wave-like equation, for a symmetric tensor, under the divergence-free constraint. The method is similar to the vector case (evolution of a magnetic field), for which the corresponding technique shall be presented first. |
||

lundi 1er février 2010 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
||