Atelier API "Ondes gravitationnelles et objets compacts"

Binary neutron star mergers in massive scalar-tensor theory: post-merger properties and gravitational wave signature

10 oct. 2024, 10:30

20m

salle du château (Observatoire de Paris - site de Meudon)

Contributed talks

Orateur

Alan Tsz Lok Lam (Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam)

Description

We study binary neutron stars in the framework of Damour-Esposito-Farese-type scalar-tensor theory of gravity with a massive scalar field using numerical relativity simulations, focusing on the properties of post-merger remnant. We found that the threshold mass for prompt collapse is raised in the presence of the excited scalar field. Our simulation results also suggest the existence of long-lived ϕ−mode in hypermassive neutron stars due to the presence of the massive scalar field which enhances the quasi-radial oscillation in the remnant. We investigate the descalarization condition in hypermassive neutron stars and discover a distinctive signature in post-merger gravitational waves.