Fast Radio Bursts from the Decay of Cosmic String Cusps

Abstract

We explore the possibility that Fast Radio Bursts are due to the annihilation of cusps on cosmic string loops. We compute the energy released in the annihilation events in the radio region, the expected event rate, and the time scale of the bursts. We find that the energy and event rates are sufficiently high and the time scale is sufficiently small to explain the current data. We predict how the event rate will change as the resolution of telescopes improves. Since the burst rate depends on the string tension, future data will allow the determination of the tension.

Cosmic Rays and Spectral Distortions from Collapsing Textures

“…For example, the extra photon radiation at radio wavelengths may lead to an absorption feature [25] in the global 21cm signal, in the same way that decaying cosmic string loops may yield such a signal [26]. It is unlikely, however, that unwinding events can explain the origins of fast radio bursts (FRBs), as the decay pattern to low energy photons suffers from similar problems to those photons produced off of cosmic string cusps [27]. On top of that, the number density of these undwinding events is much smaller than that of string loops studied in [27], and so this model would also suffer from being unable to explain the current number densities of FRBs.…”

“…Since the energy release mechanism we have is insensitive to the transition between the y and µ eras, we can simply use (27) once again to compute our contribution to the y distortion. Doing this yields…”

Massive black holes at high redshifts from superconducting cosmic strings

“…Besides sourcing a gravitational wave background, string loops have been considered in a wide variety of contexts. Work has been done on modelling the progenitors of fast radio bursts (FRBs), where annihilations of microstructure (cusps) on both regular [54] and superconducting loops [55][56][57][58][59][60][61] could source the signal. In addition, these cusp annihilations may also influence the global 21-cm signal by injecting additional photons into the background, heating it up.…”

Intermediate Mass Black Hole Seeds from Cosmic String Loops

“…The current limits are Gµ < 10 −10 , and the recent NANOgrav results could [29] be interpreted as being due to cosmic strings with a value of Gµ of this order of magnitude. The cusp annihilation process also produces jets of particles whose role in contributing to the spectrum of high energy cosmic rays was explored in [27], and which will contribute to the global 21cm signal [28], which may play a role in explaining Fast Radio Bursts [30], and in magnetogenesis [31].…”