Matter density perturbations and effective gravitational constant in modified gravity models of dark energy
| dc.creator | Tsujikawa, Shinji | |
| dc.date | 2007-05-08 | |
| dc.date | 2007-11-06 | |
| dc.date.accessioned | 2026-07-07T12:13:29Z | |
| dc.date.available | 2026-07-07T12:13:29Z | |
| dc.description | We derive the equation of matter density perturbations on sub-horizon scales for a general Lagrangian density f(R, phi, X) that is a function of a Ricci scalar R, a scalar field phi and a kinetic term X=-(nabla phi)^2/2. This is useful to constrain modified gravity dark energy models from observations of large-scale structure and weak lensing. We obtain the solutions for the matter perturbation delta_m as well as the gravitational potential Phi for some analytically solvable models. In a f(R) dark energy model with the Lagrangian density f(R)=alpha R^{1+m}-Lambda, the growth rates of perturbations exhibit notable differences from those in the standard Einstein gravity unless m is very close to 0. In scalar-tensor models with the Lagrangian density f=F(phi)R+2p(phi,X) we relate the models with coupled dark energy scenarios in the Einstein frame and reproduce the equations of perturbations known in the current literature by making a conformal transformation. We also estimate the evolution of perturbations in both Jordan and Einstein frames when the energy fraction of dark energy is constant during the matter-dominated epoch. | |
| dc.description | 11 pages, no figures, typos are corrected, version to appear in Physical Review D | |
| dc.identifier | https://arxiv.org/abs/0705.1032 | |
| dc.identifier | http://arxiv.org/abs/0705.1032 | |
| dc.identifier | Phys.Rev.D76:023514,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.76.023514 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/210863 | |
| dc.subject | Astrophysics | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.subject | High Energy Physics - Theory | |
| dc.title | Matter density perturbations and effective gravitational constant in modified gravity models of dark energy | |
| dc.type | text |