Rastall’s theory is a modification of Einstein’s theory of gravity where the covariant divergence of the stress-energy tensor is no more vanishing, but is proportional to the gradient of the Ricci scalar. The motivation of this theory is to investigate a possible non-minimal coupling of matter fields to geometry which, being proportional to the curvature scalar, may represent an effective description of quantum gravity effects. Non-conservation of the stress-energy tensor, via Bianchi identities, implies new field equations which have been recently used in a cosmological context, leading to some results of interest. In this paper we adopt Rastall’s theory to reproduce some features of the effective Friedmann equation emerging from loop quantum cosmology. We determine a class of bouncing cosmological solutions and comment about the possibility of employing these models as effective descriptions of a full quantum theory.

Bouncing solutions in Rastall`s theory with a barotropic fluid

PIATTELLA O;
2013-01-01

Abstract

Rastall’s theory is a modification of Einstein’s theory of gravity where the covariant divergence of the stress-energy tensor is no more vanishing, but is proportional to the gradient of the Ricci scalar. The motivation of this theory is to investigate a possible non-minimal coupling of matter fields to geometry which, being proportional to the curvature scalar, may represent an effective description of quantum gravity effects. Non-conservation of the stress-energy tensor, via Bianchi identities, implies new field equations which have been recently used in a cosmological context, leading to some results of interest. In this paper we adopt Rastall’s theory to reproduce some features of the effective Friedmann equation emerging from loop quantum cosmology. We determine a class of bouncing cosmological solutions and comment about the possibility of employing these models as effective descriptions of a full quantum theory.
2013
http://dx.doi.org/10.1134/S0202289313030109
Rastall's theory; Bouncing cosmology
Gabriel F., Silva; Piattella, O; Julio C., Fabris; Luciano, Casarini; Taislane O., Barbosa
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11383/2125152
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