General Properties of the Gravitational Wave Spectrum from Phase Transitions

Abstract

In this paper we discuss some general aspects of the gravitational wave background arising from post-inflationary short-lasting cosmological events such as phase transitions. We concentrate on the physics which determines the shape and the peak frequency of the gravitational wave spectrum. We then apply our general findings to the case of bubble collisions during a first order phase transition and compare different results in the recent literature.

11 pages, 8 figures; v2: minor clarifications, published version