Universal Relations for Binary Neutron Star Mergers with Long-lived Remnants

In the last 25 years, equation of state independent - or (approximately) universal - relations have been developed to infer neutron star parameters from gravitational wave observations. However, these works have mostly been focused on singular neutron stars, while observational efforts will be focused on binary neutron star (BNS) mergers. This thesis presents a first attempt at perturbatively deriving universal relations for binary neutron star mergers with long-lived neutron star remnants, confirming previous results relating pre-merger binary tidal deformabilities to the f-mode frequency of the post-merger object and deriving a combined relation that relates the pre-merger binary tidal deformability of a BNS to the effective compactness of a long-lived neutron star remnant.

Format: Paperback / softback
Length: 65 pages
Publication date: 29 March 2022
Publisher: Springer Fachmedien Wiesbaden

In the past quarter-century, a significant body of research has emerged, unveiling diverse equation of state-independent or (approximately) universal relations that enable the inference of neutron star parameters from gravitational wave observations. These endeavors, however, have predominantly concentrated on singular neutron stars, while our current and forthcoming observational efforts will primarily revolve around binary neutron star (BNS) mergers. Considering these contextual factors, the past five years have witnessed an increase in attempts to establish universal connections linking BNS pre-merger neutron stars to stellar parameters of the post-merger object, primarily driven by numerical relativity simulations.

In this thesis, the author undertakes a pioneering endeavor to perturbatively derive universal relations for binary neutron star mergers involving long-lived neutron star remnants. Notably, the author successfully corroborates previous findings linking pre-merger binary tidal deformabilities to the f-mode frequency of the post-merger object. By combining this result with recent advancements in computing the f-mode frequency of fast rotating neutron stars, the author further derives a combined relation that establishes a connection between the pre-merger binary tidal deformability of a BNS and the effective compactness of a long-lived neutron star remnant. Furthermore, the author proposes a direct relation between these quantities, exhibiting enhanced accuracy.

Weight: 122g
Dimension: 210 x 148 (mm)
ISBN-13: 9783658368401
Edition number: 1st ed. 2022