First Test of High Frequency Gravity Waves from Inflation using ADVANCED LIGO

Abstract

Inflation models ending in a first order phase transition produce gravitational waves (GW) via bubble collisions of the true vacuum phase. We demonstrate that these bubble collisions can leave an observable signature in Advanced LIGO, an upcoming ground-based GW experiment. These GW are dependent on two parameters of the inflationary model: $\varepsilon$ represents the energy difference between the false vacuum and the true vacuum of the inflaton potential, and $\chi$ measures how fast the phase transition ends ($\chi \sim$ the number of e-folds during the actual phase transition). Advanced LIGO will be able to test the validity of single-phase transition models within the parameter space $10^7 \rm{GeV}\lesssim \varepsilon^{1/4} \lesssim 10^{10} \rm{GeV}$ and $0.19 \lesssim \chi \lesssim 1$. If inflation occurred through a first order phase transition, then Advanced LIGO could be the first to discover high frequency GW from inflation.