Résumé / Abstract Seminaire_GReCO
SÉMINAIRE DU GRECO

"Relativistic stars in f[R] and chameleon theories"

E. Babichev
Laboratoire AstroParticule et Comologie, Université Paris Diderot (Paris, France)

We study relativistic stars in the context of scalar tensor theories of gravity that try to account for the observed cosmic acceleration, more specifically in two types of models: chameleon and f(R) theories. Using a relaxation algorithm, we construct numerically static relativistic stars, both for constant energy density configurations and for a polytropic equation of state. We can reach a gravitational potential up to ? ? 0.3, even in f(R) theories with a singularity at large curvatures. However, we find static configurations only if the pressure does not exceed three times the energy density, except possibly in a small region of the star. This constraint is satisfied by the equations of state proposed for realistic neutron stars.

lundi 9 novembre 2009 - 11:00
Salle des séminaires Évry Schatzman,
Institut d'Astrophysique de Paris

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