TY  - JOUR
AU  - Beltran Jimenez, J.
AU  - Heisenberg, L.
AU  - Olmo, G. J.
PY  - 2015
DA  - 2015//
TI  - Tensor perturbations in a general class of Palatini theories
T2  - J. Cosmol. Astropart. Phys.
JO  - Journal of Cosmology and Astroparticle Physics
SP  - 026
EP  - 16pp
VL  - 06
IS  - 6
PB  - Iop Publishing Ltd
KW  - modified gravity
KW  - inflation
KW  - gravity
KW  - dark energy theory
AB  - We study a general class of gravitational theories formulated in the Palatini approach and derive the equations governing the evolution of tensor perturbations. In the absence of torsion, the connection can be solved as the Christoffel symbols of an auxiliary metric which is non-trivially related to the space-time metric. We then consider background solutions corresponding to a perfect fluid and show that the tensor perturbations equations (including anisotropic stresses) for the auxiliary metric around such a background take an Einstein-like form. This facilitates the study in a homogeneous and isotropic cosmological scenario where we explicitly establish the relation between the auxiliary metric and the spacetime metric tensor perturbations. As a general result, we show that both tensor perturbations coincide in the absence of anisotropic stresses.
SN  - 1475-7516
UR  - http://arxiv.org/abs/1504.00295
UR  - https://doi.org/10.1088/1475-7516/2015/06/026
DO  - 10.1088/1475-7516/2015/06/026
LA  - English
N1  - WOS:000359215400027
ID  - BeltranJimenez_etal2015
ER  -