Relativistic stars in f(R) and scalar-tensor theories

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.124051· OSTI ID:21413233

Babichev, Eugeny ^[1]; Langlois, David ^[1]

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1. APC, UMR 7164 (CNRS-Universite Paris 7), 10 rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France)

We study relativistic stars in the context of scalar-tensor theories of gravity that try to account for the observed cosmic acceleration and satisfy the local gravity constraints via the chameleon mechanism. More specifically, we consider two types of models: scalar-tensor theories with an inverse power law potential 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 {Phi}{approx}0.3 at the surface of the star, even in f(R) theories with an 'unprotected' curvature singularity. However, we find static configurations only if the pressure does not exceed one third of the energy density, except possibly in a limited region of the star (otherwise, one expects tachyonic instabilities to develop). This constraint is satisfied by realistic equations of state for neutron stars.

• OSTI ID: 21413233
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 12; Other Information: DOI: 10.1103/PhysRevD.81.124051; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCELERATION
ALGORITHMS
CONFIGURATION
ENERGY DENSITY
EQUATIONS OF STATE
GRAVITATION
INSTABILITY
NEUTRON STARS
RELATIVISTIC RANGE
RELAXATION
SCALAR FIELDS
SINGULARITY
SURFACES
TACHYONS
TENSOR FIELDS
ELEMENTARY PARTICLES
ENERGY RANGE
EQUATIONS
MATHEMATICAL LOGIC
POSTULATED PARTICLES
STARS