Résumé / Abstract Seminaire_GReCO
SÉMINAIRE DU GRECO

"Separating expansion from collapse and generalizing TOV condition in spherically symmetric models with pressure, with ?-CDM examples"

M. Le Delliou
Univ. Autonoma (Madrid, Espagne)

The Press-Schechter scheme for mass functions invokes Birkhoff''s theorem in the spherical collapse that yields non-linear collapse time. However, the theorem is only proven for asymptotic flatness (vacuum background). We investigate spherically symmetric solutions with pressure and discuss the existence of a dividing shell separating expanding and collapsing regions, for which we obtain gauge invariant conditions relating not only the intrinsic spatial curvature of the shells to the mass, but also a function of the pressure which we introduce and that generalises the Tolman-Oppenheimer-Volkov equilibrium condition.

jeudi 8 avril 2010 - 11:00
Salle des séminaires Évry Schatzman,
Institut d'Astrophysique de Paris

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