6533b827fe1ef96bd1285dd4

RESEARCH PRODUCT

Metric-Palatini gravity unifying local constraints and late-time cosmic acceleration

Gonzalo J. OlmoTomi S. KoivistoTomi S. KoivistoTiberiu HarkoFrancisco S. N. Lobo

subject

PhysicsHigh Energy Physics - TheoryNuclear and High Energy PhysicsSolar SystemCosmology and Nongalactic Astrophysics (astro-ph.CO)COSMIC cancer database010308 nuclear & particles physicsFOS: Physical sciencesPerturbation (astronomy)General Relativity and Quantum Cosmology (gr-qc)01 natural sciencesCosmologyGeneral Relativity and Quantum Cosmologysymbols.namesakeTheoretical physicsGeneral Relativity and Quantum CosmologyClassical mechanicsHigh Energy Physics - Theory (hep-th)0103 physical sciencessymbolsf(R) gravity010306 general physicsScalar fieldLagrangianAstrophysics - Cosmology and Nongalactic Astrophysics

description

We present a novel approach to modified theories of gravity that consists of adding to the Einstein-Hilbert Lagrangian an f(R) term constructed a la Palatini. Using the respective dynamically equivalent scalar-tensor representation, we show that the theory can pass the Solar System observational constraints even if the scalar field is very light. This implies the existence of a long-range scalar field, which is able to modify the cosmological and galactic dynamics, but leaves the Solar System unaffected. We also verify the absence of instabilities in perturbations and provide explicit models which are consistent with local tests and lead to the late-time cosmic acceleration.

yearjournalcountryeditionlanguage
2011-10-05
10.1103/physrevd.85.084016http://arxiv.org/abs/1110.1049