Gravitational Radiation Generated by Magnetic Fields in Cosmological Phase Transitions

Abstract

We study gravitational waves (GWs) generated by the cosmological magnetic fields induced via bubble collisions during the electroweak(EW) and QCD phase transitions (PT). Our derivation of magnetic fields produced in bubble collisions is based on the use of the fundamental MSSM EW and QCD Lagrangians. The GWs spectrum is computed using a magnetohydrodynamic (MHD) turbulence model. We find that the EWPT GW spectrum amplitude peaks at frequency approximately 1-2 mHz, and is order of $10^{-20}-10^{-21}$, and thus this signal is possibly detectable by Laser Interferometer Space Antenna (LISA). On the other hand, the GW signal from the QCDPT is outside the LISA sensitivity bands.