Particle emission and gravitational radiation from cosmic strings: observational constraints

Abstract: We account for particle emission and gravitational radiation from cosmic string loops to determine their effect on the loop distribution and observational signatures of strings. The effect of particle emission is that the number density of loops no longer scales. This results in a high frequency cutoff on the stochastic gravitational wave background, but we show that the expected cutoff is outside the range of current and planned detectors. Particle emission from string loops also produces a diffuse gamma ray background that is sensitive to the presence of kinks and cusps on the loops. However, both for kinks and cusps, and with mild assumptions about particle physics interactions, current diffuse gamma-ray background observations do not constrain $G\mu$.