HighOrder Multipole and Binary Love Number Universal Relations
Abstract
Using a data set of approximately 2 million phenomenological equations of state consistent with observational constraints, we construct new equationofstateinsensitive universal relations that exist between the multipolar tidal deformability parameters of neutron stars, $\Lambda_l$, for several highorder multipoles ($l = 5,6,7,8$). We confirm the existence of a universal relation between the radius of the $1.4 M_\odot$ NS, $R_{1.4}$ and the reduced tidal parameter of the binary, $\tilde{\Lambda}$, and the chirp mass. We extend this relation to a large number of chirp masses and to the radii of isolated NSs of different mass $M$, $R_M$. We find that there is an optimal value of $M$ for every $\mathcal{M}$ such that the uncertainty in the estimate of $R_M$ is minimized when using the relation. We discuss the utility and implications of these relations for the upcoming LIGO O4 run and thirdgeneration detectors.
 Publication:

Universe
 Pub Date:
 September 2021
 DOI:
 10.3390/universe7100368
 arXiv:
 arXiv:2109.01159
 Bibcode:
 2021Univ....7..368G
 Keywords:

 eutron star;
 equation of state;
 universal relation;
 Astrophysics  High Energy Astrophysical Phenomena;
 General Relativity and Quantum Cosmology
 EPrint:
 14 pages, 6 figures, 3 tables Replacement of older version of manuscript. A few small errors were found in the previous version of the manuscript that do not affect the scientific findings of the paper. They are corrected in this version