RT Book, Section
T1 Cosmological density perturbations in modified gravity theories
A1 Cruz Dombriz, Álvaro de la
A1 Dobado González, Antonio
A1 López Maroto, Antonio
AB In the context of f(R) theories of gravity, we study the cosmological evolution of scalar perturbations by using a completely general procedure. We find that the exact fourth-order differential equation for the matter density perturbations in the longitudinal gauge, reduces to a second-order equation for sub-Hubble modes. This simplification is compared with the standard (quasi-static) equation used in the literature. We show that for general f(R) functions the quasi-static approximation is not justified. However for those f(R) adequately describing the present phase of accelerated expansion and satisfying local gravity tests, it does give a correct description for the evolution of perturbations.
PB Amer Inst Physics
SN 978-0-7354-0658-2
SN 0094-243X
YR 2009
FD 2009
LK https://hdl.handle.net/20.500.14352/53241
UL https://hdl.handle.net/20.500.14352/53241
LA eng
NO © American Institute of Physics. Spanish Relativity Conference (31. 2008. Salamanca, España).We would like to thank J. A. R. Cembranos and J. Beltran. This work has been supported by the DGICYT (Spain) under projects FPA 2004-02602 and 2005-02327, CAM/UCM 910309 and by UCM-SantanderPR34/07-15875
NO DGICYT (Spain)
NO UCM-Santander
DS Docta Complutense
RD 4 abr 2025