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Article
Report number	gr-qc/9306015 ; CERN-TH-6836-93 ; DFTT-26-93 ; CERN-TH-6836-93 ; DFTT-93-26
Title	Squeezed thermal vacuum and the maximum scale for inflation
Author(s)	Gasperini, M. (CERN) ; Giovannini, Massimo (Turin U. ; INFN, Turin) ; Veneziano, G. (CERN)
Affiliation	(CERN) ; (Univ. Torino) ; (INFN Torino)
Publication	1993
Imprint	Mar 1993
Number of pages	15
In:	Phys. Rev. D 48 (1993) 439-443
DOI	10.1103/PhysRevD.48.R439
Subject category	General Theoretical Physics
Abstract	We consider the stimulated emission of gravitons from an initial state of thermal equilibrium, under the action of the cosmic gravitational background field. We find that the low-energy graviton spectrum is enhanced if compared with spontaneous creation from the vacuum; as a consequence, the scale of inflation must be lowered, in order not to exceed the observed CMB quadrupole anisotropy. This effect is particularly important for models based on a symmetry-breaking transition which require, as initial condition, a state of thermal equilibrium at temperatures of the order of the inflation scale.

Corresponding record in: Inspire
Email contact: GASPERINI@to.infn.it