Gravitational wave from extreme mass-ratio inspirals as a probe of extra dimensions

TL;DR

This paper explores how gravitational wave signals from extreme mass-ratio inspirals can be used to detect or constrain the existence of extra dimensions through the effects of a tidal charge on black hole properties.

Contribution

It introduces the impact of a tidal charge in braneworld black holes on EMRI gravitational wave signals and discusses how future detectors can test for extra dimensions.

Findings

LISA can significantly constrain the tidal charge parameter.

Tidal charge affects gravitational wave flux and orbital phase.

Future space-based detectors can probe extra dimensions more effectively.

Abstract

The field of gravitational waves is rapidly progressing due to the noticeable advancements in the sensitivity of gravitational-wave detectors that has enabled the detection prospects of binary black hole mergers. Extreme mass ratio inspiral (EMRI) is one of the most compelling and captivating binary systems in this direction, with the detection possibility by the future space-based gravitational wave detector. In this article, we consider an EMRI system where the primary or the central object is a spherically symmetric static braneworld black hole that carries a \textit{tidal charge} $Q$. We estimate the effect of the tidal charge on total gravitational wave flux and orbital phase due to a non-spinning secondary inspiralling the primary. We further highlight the observational implications of the tidal charge in EMRI waveforms. We show that LISA (Laser Interferometer Space Antenna) observations can put a much stronger constraint on this parameter than black hole shadow and ground-based gravitational wave observations, which can potentially probe the existence of extra dimensions.