title: Enhanced polarization of the cosmic microwave background radiation from thermal gravitational waves.
abstract: If inflation was preceded by a radiation era, then at the time of inflation there will exist a decoupled thermal distribution of gravitons. Gravitational waves generated during inflation will be amplified by the process of stimulated emission into the existing thermal distribution of gravitons. Consequently, the usual zero temperature scale invariant tensor spectrum is modified by a temperature dependent factor. This thermal correction factor amplifies the B-mode polarization of the cosmic microwave background radiation by an order of magnitude at large angles, which may now be in the range of observability of the Wilkinson Microwave Anisotropy Probe.
authors.affiliation: Physical Research Laboratory, Navrangpura, Ahmedabad-380 009, India.
authors.forename: Kaushik
authors.initials: K
authors.lastname: Bhattacharya
authors.forename: Subhendra
authors.initials: S
authors.lastname: Mohanty
authors.forename: Akhilesh
authors.initials: A
authors.lastname: Nautiyal