TY - JOUR

T1 - Quantum corrections to the cosmological evolution of conformally coupled fields

AU - Cembranos, Jose A.R.

AU - Olive, Keith A

AU - Peloso, Marco

AU - Uzan, Jean Philippe

PY - 2009/11/9

Y1 - 2009/11/9

N2 - Because the source term for the equations of motion of a conformally coupled scalar field, such as the dilaton, is given by the trace of the matter energy momentum tensor, it is commonly assumed to vanish during the radiation dominated epoch in the early universe. As a consequence, such fields are generally frozen in the early universe. Here we compute the finite temperature radiative correction to the source term and discuss its consequences on the evolution of such fields in the early universe. We discuss in particular, the case of scalar tensor theories of gravity which have general relativity as an attractor solution. We show that, in some cases, the universe can experience an early phase of contraction, followed by a non-singular bounce, and standard expansion. This can have interesting consequences for the abundance of thermal relics; for instance, it can provide a solution to the gravitino problem. We conclude by discussing the possible consequences of the quantum corrections to the evolution of the dilaton.

AB - Because the source term for the equations of motion of a conformally coupled scalar field, such as the dilaton, is given by the trace of the matter energy momentum tensor, it is commonly assumed to vanish during the radiation dominated epoch in the early universe. As a consequence, such fields are generally frozen in the early universe. Here we compute the finite temperature radiative correction to the source term and discuss its consequences on the evolution of such fields in the early universe. We discuss in particular, the case of scalar tensor theories of gravity which have general relativity as an attractor solution. We show that, in some cases, the universe can experience an early phase of contraction, followed by a non-singular bounce, and standard expansion. This can have interesting consequences for the abundance of thermal relics; for instance, it can provide a solution to the gravitino problem. We conclude by discussing the possible consequences of the quantum corrections to the evolution of the dilaton.

KW - Modified gravity

KW - Physics of the early universe

KW - String theory and cosmology

UR - http://www.scopus.com/inward/record.url?scp=70350669634&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70350669634&partnerID=8YFLogxK

U2 - 10.1088/1475-7516/2009/07/025

DO - 10.1088/1475-7516/2009/07/025

M3 - Article

AN - SCOPUS:70350669634

VL - 2009

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - 7

M1 - 025

ER -