Thermal Gravitational Waves from Primordial Black Holes

TL;DR

This paper estimates the production and energy of thermal gravitational waves from primordial black holes, gamma ray bursts, and dense astrophysical objects, highlighting potential sources of high-frequency gravitational radiation.

Contribution

It provides the first detailed estimates of thermal gravitational wave emission from primordial black holes and their cumulative energy contribution in the universe.

Findings

Primordial black holes can generate significant thermal gravitational waves.

The integrated energy of these waves over the universe's volume is substantial.

Gamma ray bursts and jets are also notable sources of thermal gravitational waves.

Abstract

Thermal gravitational waves can be generated in various sources such as, in the cores of stars, white dwarfs and neutron stars due to the fermion collisions in the dense degenerate Fermi gas. Such high frequency thermal gravitational waves can also be produced during the collisions in a gamma ray burst or during the final stages of the evaporation of primordial black holes. Here we estimate the thermal gravitational waves from primordial black holes and estimate the integrated energy of the gravitational wave emission over the entire volume of the universe and over Hubble time. We also estimate the gravitational wave flux from gamma ray bursts and jets.