Structure of Compact Stars in Palatini f (R) Gravity

GARCÍA, F.; TEPPA-PANIA, F.A.; PEREZ-BERGLIAFFA, S.E.; ORELLANA, M.; G.E. ROMERO

Buenos Aires

Congreso; Gravitation, Relativistic Astrophysics and Cosmology, Second Argentinian-Brazilian Meeting; 2014

CONICET, CLAF, ANPCYT, IAR, IAFE

The study of the structure of compact objects in the frame of modified theories of gravity can be useful to constrain f (R)-theories in the strong gravitational regime. In particular, changes in the structure of compact stars under the generalization of the Langrangian density f(R)=R+alpha*R**2, namely squared-gravity, have been recently explored using the metric formalism. In this work we analyze configurations of neutron stars in squared- gravity using the Palatini formalism. In this formalism, the field equations are of second order, as in General Relativity, and the modified Tolman-Oppenheimer-Volkoff equations for a spherically-symmetric and static metric can be derived exactly. The numerical integration of the structure equations allows us to study the mass-radius configurations and the behavior of internal pro- files. We compare our results with those obtained using General Relativity.