SÉMINAIRE DU GRECO
"Relativistic stars in f[R] and chameleon theories" |
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E. Babichev |
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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. |
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lundi 9 novembre 2009 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
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