Squeezed thermal vacuum and the maximum scale for inflation

1993/06/10 by M. Gasperini, Massimo Giovannini, M. Giovannini +1 · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Relativity and Gravitational Theory #astro-ph #gr-qc #hep-th

paper · pdf · doi:10.1103/physrevd.48.r439

published as Phys.Rev.D48:439-443,1993 · 13 pages, plain tex, three figures available upon request, to appear in Phys.Rev.D, CERN-TH.6836/93

arxiv created 1993/06/10 · openalex publication_date 1993/07/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

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 an initial condition, a state of thermal equilibrium at temperatures of the order of the inflation scale.

Citations

• Dilaton contributions to the cosmic gravitational wave background
• Quantized Fields and Particle Creation in Expanding Universes. I

Cited by

• Relic gravitons, dominant energy condition, and bulk viscous stresses
• Assigning quantum-mechanical initial conditions to cosmological perturbations