Nonlinear structure formation in gravity theories beyond general relativity

We investigate the effects of modified gravity theories, in particular, the symmetron and f(R) gravity, on the nonlinear regime of structure formation. In particular, we investigate the velocity dispersion of galaxy clusters as a function of the halo masses, how the matter power spectra depend on the coupling, range and screening scale of the fifth force, and on possible ways of detecting violations of the equivalence principle using the mass inferred via lensing methods versus the mass inferred via dynamical methods.

Download Full-text

Probing screened modified gravity with nonlinear structure formation

International Journal of Modern Physics D ◽

10.1142/s0218271818300033 ◽

2018 ◽

Vol 27 (04) ◽

pp. 1830003 ◽

Cited By ~ 2

Author(s):

David F. Mota

Keyword(s):

Structure Formation ◽

Modified Gravity ◽

Equivalence Principle ◽

Velocity Dispersion ◽

Power Spectra ◽

Nonlinear Structure ◽

Fifth Force ◽

Modified Gravity Theories ◽

Halo Masses ◽

Screening Scale

We review the effects of modified gravity theories, in particular the symmetron and [Formula: see text] gravity, on the nonlinear regime of structure formation. In particular, we investigate the velocity dispersion of galaxy clusters as a function of the halo masses, how the matter power spectra depend on the coupling, range, and screening scale of the fifth force, and on possible ways of detecting violations of the equivalence principle using the mass inferred via lensing methods versus the mass inferred via dynamical methods. Furthermore, we show how one could use different voids statistics as one of the most promising probes of modified gravity.

Download Full-text

ON IMPLICATIONS OF EQUIVALENCE PRINCIPLE FOR MODIFIED GRAVITY THEORIES

International Journal of Modern Physics D ◽

10.1142/s0218271811020706 ◽

2011 ◽

Vol 20 (14) ◽

pp. 2839-2845 ◽

Cited By ~ 1

Author(s):

M. M. SHEIKH-JABBARI

Keyword(s):

Modified Gravity ◽

Equivalence Principle ◽

Riemann Curvature ◽

Riemann Curvature Tensor ◽

Lovelock Gravity ◽

Modified Gravity Theory ◽

Modified Gravity Theories ◽

Levi Civita Connection ◽

Gravity Theories ◽

Einstein’S General Relativity

One of the manifestations of Einstein Equivalence Principle (EEP) is that a freely falling particle in a gravitational field is following a geodesic. In Einstein's general relativity (GR) this is built in the formulation by assuming the connection to be the Levi-Civita connection. The latter may, however, be demanded to be implied by the dynamics of a generic modified gravity theory, within the Palatini formulation. We show that for extensions of the Einstein GR which are described by a Lagrangian [Formula: see text], where gμν is the metric and Rμαβν is the Riemann curvature tensor, this manifestation of EEP is only fulfilled for a special class of Lagrangians, the Lovelock gravity theories. Our analysis also implies that within the above mentioned set of modified gravity theories only for Lovelock gravity theories metric and Palatini formulations are equivalent.

Download Full-text