Speaker
Description
We present new insights into accretion flows and their oscillations and precessions in relativistic environments of neutron stars (NSs). First, we derive a fully general relativistic analytic solution for radiation-pressure-supported equilibrium fluid tori orbiting rotating NSs in Hartle-Thorne geometry. We explore the impact of NS space-time parameters on the existence and properties of surrounding tori, especially critically thick tori (cusp tori). Additionally, we investigate the four characteristic oscillation frequencies of accretion flows around NSs, critical for understanding variability in low-mass X-ray binaries (LMXBs). We provide complete formulae and approximations for calculating radial and vertical epicyclic oscillations, as well as periastron and Lense-Thirring precession frequencies. Our results reveal that incorporating the effects of fluid flow precession into oscillation models offers a more accurate match to observed quasiperiodic oscillations than purely geodesic models. Together, these studies offer new perspectives on the influence of NS properties on accretion dynamics and its observational signatures, offering tools for probing the super-dense matter equation of state.