Gravitational wave search through electromagnetic telescopes

TL;DR

This paper investigates the conversion of gravitons to photons in cosmic magnetic fields to set upper limits on high-frequency gravitational waves, proposing a novel method for their detection via electromagnetic telescopes.

Contribution

It introduces a new approach to constrain high-frequency gravitational waves through graviton-photon conversion in magnetic fields, extending the observational frequency range.

Findings

Upper limits on stochastic gravitational waves derived for frequencies $10^{7}$Hz to $10^{35}$Hz.

Potential to constrain $h^2 \Omega_{GW}$ below unity in the $10^{18}$-$10^{23}$ Hz range.

Proposes electromagnetic telescopes as a new tool for high-frequency gravitational wave detection.

Abstract

We study the graviton-photon conversion in the magnetic fields of the Earth, the Milky Way Galaxy, and intergalactic regions. Requiring that the photon flux converted from gravitons does not exceed the observed photon flux with telescopes, we derive upper limits on the stochastic gravitational waves in frequency ranges from $10^{7}$Hz to $10^{35}$Hz. Remarkably, the upper limits on $h^2 \Omega_{{\rm GW}}$ could be less than unity in the frequency range of $10^{18}$-$10^{23}$ Hz in a specific case. The detection of gravitational waves using telescopes would open up a new avenue for high frequency gravitational wave observations.