IUCAA Brochure 2024

Neutron Stars and GW A research group at IUCAA is involved in studying Neutron Stars (NS) using Gravitational Waves (GW). Being ultra- dense, NS show a myriad of extreme properties and serve as cosmic laboratories to investigate Fundamental Physics. Their strong gravity can bend space-time a lot, and their collisions or perturbations can result in strong GW emission. Since 2017, the groundbreaking detection of GW signals from NS by the LIGO-Virgo detectors allow us to look into their interior and constrain dense matter properties. IUCAA research studies are going on to improve limits for continuous GWsearches. Over the past year, several studies looked for signatures of the Neutron Stars internal composition in unstable oscillation modes. The results showed that Nuclear Physics can be better constrained using signals from such oscillations, in both isolated or binary NS, via planned future generation GW detectors. They also investigated how such detectionsmay allowus to distinguish betweenNS and other stable families of compact stars or probe the nature of possible phase transitions in their interior. Other works imposed constraints on compact star properties using multi-disciplinary Physics (nuclear theory, heavy-ion, multi-messenger astronomy) at different densities. Tidal heating in Neutron Stars mergers was also proposed as a novel probe of strangeness in NS. Their oscillationmodes were also suggested as a new probe of the presence of darkmatter inNS.