Research Projects

With the overwhelming success of gravitational wave (GW) astronomy, our goals have become more ambitious. Not limiting ourselves to near detection, we are now interested in studying new sources and new features. The next-generation detectors will increase our scope of probing a wide range of GW sources in the universe. It is precisely the theme of the present proposal -- to probe generic binaries with next-generation GW detectors. The proposal talks about four different aspects of GW astronomy, all connected with generic binaries and next-generation detectors. A. Binaries with a spinning secondary: Motion of a spinning particle around a massive compact object forms an extreme mass ratio inspiral (EMRI), which is the primary target for the upcoming space-based GW detector Laser Interferometer Space Antenna (LISA). Obtaining the motion of a spinning particle in generic orbits is a formidable task. We aim to address this problem by using the Carter-like constant available up to linear in spin order. The key objective is to evolve these equations along with the radiation reaction force. This study will shed light on the usefulness of flux associated with Carter-like constant. In addition, we plan to address resonances appearing in the system and their possible implications on waveform systematics. B. Dark matter: Most of the studies to obtain dark matter distribution around massive compact objects assume spherical symmetry. By considering the massive object to be spinning and spacetime is stationary, dark matter distribution becomes axially symmetric, and theta dependent. For such systems, we are interested to study generic binary evolution, and how dark matter dissipates energy, momentum, and Carter-like constant. We are primarily interested to study the dephasing in emitted GWs, and how dark matter affects binary parameter estimations for next-generation detectors. C. Test of GR: The future GW detectors will play a vital role to probe strong field gravity. This project is based on the idea that, in principle, a non-GR effect may be mimicked by a GR prediction for a different orbital setup or order. We propose to employ mode excitation as a possible probe to test GR in the strong field regime. In particular, while GR prediction suggests that orbital misalignment in a binary can excite modes in Kerr spacetime, we ask whether the same also holds for a non-GR theory such as braneworld gravity. D. GW memory: The GW sources with memory are potential candidates for LISA. In this project, we are interested to study (non-linear) memory effect from highly eccentric orbits, repeating their motion a number of times. These orbits are called zoom-whirl orbits and can be potentially detectable by LISA. For the head-on collisions, both linear and non-linear memory are likely to be present. In addition to modeling, we aim to study how memory terms may impact the binary parameter estimations.