A Nearly Scale Invariant Spectrum of Gravitational Radiation from Global Phase Transitions

Jones-Smith, Katherine; Krauss, Lawrence M.; Mathur, Harsh

A Nearly Scale Invariant Spectrum of Gravitational Radiation from Global Phase Transitions

Authors

Jones-Smith, Katherine

Krauss, Lawrence M.

Mathur, Harsh

Description

Using a large N sigma model approximation we explicitly calculate the power spectrum of gravitational waves arising from a global phase transition in the early universe and we confirm that it is scale invariant, implying an observation of such a spectrum may not be a unique feature of inflation. Moreover, the predicted amplitude can be over 3 orders of magnitude larger than the naive dimensional estimate, implying that even a transition that occurs after inflation may dominate in Cosmic Microwave Background polarization or other gravity wave signals.
4 pages, PRL published version