Very high frequency gravitational wave background in the universe

TL;DR

This paper explores the potential for detecting a high-frequency gravitational wave background generated by primordial black hole evaporation, providing limits on graviton density and discussing detection prospects.

Contribution

It introduces a new focus on high-frequency gravitational waves from primordial black holes and estimates their density limits in the universe.

Findings

Primordial black holes emit an equilibrium spectrum of gravitons during evaporation.

Limits on the density of high-frequency gravitons in the universe are established.

Detection possibilities for high-frequency gravitational waves are discussed.

Abstract

Astrophysical sources of high frequency gravitational radiation are considered in association with a new interest to very sensitive HFGW receivers required for the laboratory GW Hertz experiment. A special attention is paid to the phenomenon of primordial black holes evaporation. They act like black body to all kinds of radiation, including gravitons, and, therefore, emit an equilibrium spectrum of gravitons during its evaporation. Limit on the density of high frequency gravitons in the Universe is obtained, and possibilities of their detection are briefly discussed.