Gravitational waves from melting cosmic strings

Appearance of cosmic strings in the early Universe is a common manifestation new physics typically linked to some high energy scale. In this paper, we discuss different situation, where model underlying string formation approximately scale free. String tension naturally related square temperature hot primordial plasma such setting, and hence decreases with (cosmic) time. With gravitational backreaction neglected, dynamics these melting an expanding equivalent constant Minkowski spacetime. We provide estimate for emission waves from loops. Contrary standard case, resulting spectrum markedly non-flat has characteristic falloff at frequencies below peak one. The frequency defined by lies range accessible future detectors very weak couplings involved.