Probing the gravity of a Schwarzschild black hole in the presence of a cloud of strings with EMRIs

Abstract

Here, we explore the effect of the cloud of strings (CoS) on the gravitational waveforms of extreme mass ratio inspirals (EMRIs). The EMRI system consists of a supermassive black hole (BH) and a compact stellar mass object moving around it. We begin with studying the test particle motion around the Schwarzschild BH surrounded by a CoS by using the Lagrangian formalism. Moreover, we investigated the effect of the CoS parameter on the evolution of the semi-latus rectum and eccentricity. We then turn to the exploration of the impact of the CoS parameter on the gravitational waveforms of the EMRI system. The analysis performed shows that Laser Interferometer Space Antenna (LISA) could detect the CoS imprint in gravitational waveforms when the values of the string cloud parameter $\alpha \gtrsim 2 \times 10^{-6}$.