Stochastic gravitational wave spectrum from cosmic string emitting gauge bosons and Majorana fermions

The effect of particle radiation on the spectrum of the stochastic gravitational wave background (SGWB) from cosmic strings is studied. We consider cosmic strings in an Abelian-Higgs model coupling with Majorana fermion whose mass is generated by the Higgs field, motivated by a gauged U(1) B-L model, in which the Majorana fermions are identified with right-handed neutrinos. Taking the energy loss by particle radiation into account, we evaluate the resultant SGWB spectrum and demonstrate the emergence of very high frequency cutoff due to the particle radiation.