TY  - JOUR
AU  - Harko, T.
AU  - Koivisto, T. S.
AU  - Lobo, F. S. N.
AU  - Olmo, G. J.
PY  - 2012
DA  - 2012//
TI  - Metric-Palatini gravity unifying local constraints and late-time cosmic acceleration
T2  - Phys. Rev. D
JO  - Physical Review D
SP  - 084016
EP  - 5pp
VL  - 85
IS  - 8
PB  - Amer Physical Soc
AB  - We present a novel approach to modified theories of gravity which 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.
SN  - 1550-7998
UR  - http://arxiv.org/abs/1110.1049
UR  - https://doi.org/10.1103/PhysRevD.85.084016
DO  - 10.1103/PhysRevD.85.084016
LA  - English
N1  - WOS:000302996100011
ID  - Harko_etal2012
ER  -