TY - JOUR
T1 - Aspects of string-gas cosmology at finite temperature
AU - Bassett, B. A.
AU - Borunda, M.
AU - Serone, M.
AU - Tsujikawa, S.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2003
Y1 - 2003
N2 - We study string-gas cosmology in dilaton gravity, inspired by the fact that it naturally arises in a string theory context. Our main interest is the thermodynamical treatment of the ideal string-gas and the resulting implications for the cosmology. Within an adiabatic approximation, thermodynamical equilibrium and a small, toroidal universe as initial conditions, we numerically solve the corresponding equations of motions in two different regimes describing the string-gas thermodynamics: (i) the Hagedorn regime, with a single scale factor, and (ii) an almost-radiation dominated regime, which includes the leading corrections due to the lightest Kaluza-Klein and winding modes, with two scale factors. The scale factor in the Hagedorn regime exhibits very slow time evolution with nearly constant energy and negligible pressure. By contrast, in case (ii) we find interesting cosmological solutions where the large dimensions continue to expand and the small ones are kept undetectably small.
AB - We study string-gas cosmology in dilaton gravity, inspired by the fact that it naturally arises in a string theory context. Our main interest is the thermodynamical treatment of the ideal string-gas and the resulting implications for the cosmology. Within an adiabatic approximation, thermodynamical equilibrium and a small, toroidal universe as initial conditions, we numerically solve the corresponding equations of motions in two different regimes describing the string-gas thermodynamics: (i) the Hagedorn regime, with a single scale factor, and (ii) an almost-radiation dominated regime, which includes the leading corrections due to the lightest Kaluza-Klein and winding modes, with two scale factors. The scale factor in the Hagedorn regime exhibits very slow time evolution with nearly constant energy and negligible pressure. By contrast, in case (ii) we find interesting cosmological solutions where the large dimensions continue to expand and the small ones are kept undetectably small.
UR - http://www.scopus.com/inward/record.url?scp=0042128426&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0042128426&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.67.123506
DO - 10.1103/PhysRevD.67.123506
M3 - Article
AN - SCOPUS:0042128426
VL - 67
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
SN - 1550-7998
IS - 12
ER -