Strong Seminar: Mostafizur Rahman

Title: Some Observational Implications of Extreme Mass-Ratio Inspirals (EMRIs)

Speaker: Mostafizur Rahman (Kyoto University)

Abstract: Extreme mass-ratio inspirals (EMRIs) are among the most important sources for the future space-based gravitational wave (GW) detector LISA. These systems carry a wealth of information about the physical parameters of the binaries, their surroundings, and the underlying physics governing their dynamics. In this talk, I will discuss several observational aspects of EMRIs, beginning with the opportunity to determine the nature of their constituent objects. Measuring the multipole moments of astrophysical objects through gravitational wave observations provides a novel way to distinguish black holes from other astrophysical objects. I will describe the gravitational wave radiation from an EMRI system consisting of a supermassive black hole (the primary object) and a spinning stellar-mass compact object (the secondary object). The quadrupolar deformation induced by the spin of the secondary varies among different astrophysical objects. We compute the effect of this quadrupolar deformation on the gravitational waveform and estimate whether LISA will be able to distinguish between different astrophysical objects based on gravitational wave observations. Additionally, I will discuss beyond-general-relativistic corrections and environmental effects on the gravitational waveform.