The constraint on modified black holes with extreme mass ratio inspirals

TL;DR

This paper investigates how string theory corrections to black holes affect gravitational waves from extreme mass-ratio inspirals, assessing the potential to detect deviations from general relativity with future space-based detectors.

Contribution

It introduces a model of deformed black holes with a deviation parameter and analyzes their impact on gravitational wave signals, providing constraints on modifications to black hole physics.

Findings

Constraint on deviation parameter: Δα ≤ 10^{-5}

Detection potential is similar with or without time-delay interferometry

Highlights importance of EMRI observations for testing string theory effects

Abstract

The low-energy effective action of String Theory introduces corrections to the dilaton-graviton sector, resulting in deformed black holes beyond general relativity. We analyze extreme mass-ratio inspiral systems (EMRIs), where a stellar-mass object spirals into a slowly rotating supermassive black hole including a distinct deviation parameter. This study examines the effects of this deformation on gravitational wave fluxes, orbital evolution, and phase dynamics, incorporating leading-order post-Newtonian corrections. With one-year observations of EMRIs, we employ the Fisher information matrix method to evaluate the potential for detecting deviations from general relativity through space-based gravitational wave detectors that utilize time-delay interferometry to suppress laser noise. The constraint on modified black holes, $\Delta\alpha \preceq 10^{-5}$, is almost the same with and without the time-delay interferometry combination. This analysis enhances our understanding and underscores the crucial role of observations in advancing gravitational phenomena within String Theory.