Abstract
Direct detection of gravitational waves and binary black hole mergers have proven to be remarkable investigations of general relativity. In order to have a definitive answer as to whether the black hole spacetime under test is the Kerr or non-Kerr, one requires accurate mapping of the metric. Since EMRIs are perfect candidates for space-based detectors, Laser Interferometer Space Antenna (LISA) observations will serve a crucial purpose in mapping the spacetime metric. In this article, we consider such a study with the Johannsen spacetime that captures the deviations from the Kerr black hole and further discuss their detection prospects. We analytically derive the leading order post-Newtonian corrections in the average loss of energy and angular momentum fluxes generated by a stellar-mass object exhibiting eccentric equatorial motion in the Johannsen background. We further obtain the orbital evolution of the inspiralling object within the adiabatic approximation and estimate the orbital phase. We lastly provide the possible detectability of deviations from the Kerr black hole by estimating gravitational wave dephasing and highlight the crucial role of LISA observations.
Shailesh Kumar
Postdoctoral Fellow
I am currently working as a Post-Docotral Fellow (N-PDF) at the Indian Institute of Technology, Gandhinagar, India. My research interest encompasses various aspects of gravitation theory, broadly black holes and gravitational waves. I am currently working on projects related to black hole perturbation techniques, extreme mass-ratio inspirals (EMRIs), tidal effects and post-Newtonian framework. My work during the PhD provides an understanding of the gravitational memory effect emerging near the horizon of black holes and its connection with asymptotic symmetries. I am also exploring the possibilities to have observational signatures of such symmetries.