Novel understanding of Cosmological Phenomena using Fast Radio Bursts

TL;DR

This paper explores the potential of fast radio bursts (FRBs) to probe cosmological phenomena, focusing on ultra-high-frequency gravitational waves and primordial black holes, and discusses how future detections could test these theories.

Contribution

It introduces the hypothesis that ultra-high-frequency GWs could generate FRBs and examines how modified gravity affects FRB lensing, providing new ways to test cosmological models.

Findings

Detection of continuous GWs near FRBs could support the GZ mechanism.

Modified gravity may cause screening effects on FRB lensing.

Upcoming telescopes like HIRAX could detect lensed FRBs for testing theories.

Abstract

Fast radio bursts (FRBs) offer unique probes of diverse cosmological phenomena due to their characteristic properties, including short duration timescale and high dispersion measure. This study investigates two distinct theoretical frameworks: the Gertsenshtein-Zel'dovich (GZ) mechanism for ultra-high-frequency gravitational waves (GWs) and fraction of dark matter in primordial mass black holes. We explore the hypothesis that ultra-high-frequency GWs could be responsible for FRB generation. Consequently, the detection of continuous GWs signal from the vicinity of an FRB by current or future detectors would disfavour merger-based FRB formation models and lend significant credence to the GZ theory, which postulates the existence of high-frequency GWs. Moreover, we examine the effects of modified gravity on the gravitational lensing of FRBs and thereby put constraints on the fraction of primordial mass black holes made up of dark matter. Our analysis suggests that modified gravity introduces a screening effect on lensing, analogous to the scattering effect by plasma on light rays. We further discuss the expected detection rates of FRBs as well as lensed FRBs with upcoming radio telescopes, primarily HIRAX.