English

Rotation-dependent $I$-Love-$Q$-$\delta M$ relations in perturbation theory

General Relativity and Quantum Cosmology 2026-01-13 v1 High Energy Astrophysical Phenomena Solar and Stellar Astrophysics

Abstract

The so-called II-Love-QQ relations link some normalized versions of the moment of inertia, the Love number, and the quadrupole moment of a star. These relations, in principle, enable the inference of two of the quantities given the third. However, their use has been limited because the normalized versions of the multipole moments rely on the static mass derived from the Tolman-Oppenheimer-Volkoff equation, which is not directly observable. In this work, using perturbation theory, we find that the II-Love-QQ relations can also be formulated in terms of an alternative set of normalized quantities that do not depend on the static mass, but on the actual (observable) mass.

Keywords

Cite

@article{arxiv.2601.07734,
  title  = {Rotation-dependent $I$-Love-$Q$-$\delta M$ relations in perturbation theory},
  author = {Eneko Aranguren},
  journal= {arXiv preprint arXiv:2601.07734},
  year   = {2026}
}