Detection relic gravitational waves in thermal case by using Adv.LIGO data of GW150914

TL;DR

This paper explores the potential detection of thermal relic gravitational waves using Adv.LIGO data from GW150914, highlighting the impact of thermal spectra on amplitude and early universe evolution.

Contribution

It introduces the concept of a modified amplitude for relic gravitational waves and assesses the detectability of thermal spectra with current detectors, providing bounds on inflation parameters.

Findings

Possible detection of thermal spectrum with Adv.LIGO data

Upper bounds on inflationary parameters β and β_s

Implications for understanding inflation and reheating stages

Abstract

The thermal spectrum of relic gravitational waves causes the new amplitude that called `modified amplitude'. Our analysis shows that, there exist some chances for detection of the thermal spectrum in addition to the usual spectrum by Adv.LIGO data of GW150914 and detector based on the maser light (Dml). The behavior of the inflation and reheating stages are often known as power law expansion like $ S(\eta)\propto \eta^{1+\beta}$, $S(\eta)\propto \eta^{1+\beta_s}$ respectively. The $\beta$ and $\beta_s$ have an unique effect on the shape of the spectrum. We find some upper bounds on the $\beta$ and $\beta_s$ by comparison the usual and the thermal spectrum with the Adv.LIGO and Dml. As this result modifies our information about the nature of the evolution of inflation and reheating stages.