We investigate the properties of post-merger remnants of binary neutron star mergers in the framework of Damour-Esposito-Farese-type scalar-tensor theory of gravity with a massive scalar field by numerical relativity simulation. It is 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.
@article{arxiv.2406.05211,
title = {Binary neutron star mergers in massive scalar-tensor theory: Properties of post-merger remnants},
author = {Alan Tsz-Lok Lam and Hao-Jui Kuan and Masaru Shibata and Karim Van Aelst and Kenta Kiuchi},
journal= {arXiv preprint arXiv:2406.05211},
year = {2024}
}