Maximum mass, moment of inertia and compactness of relativistic stars

By C. Breu, Luciano Rezzolla. 2016

233 citations recorded by the source corpus.

A number of recent works have highlighted that it is possible to express the properties of general-relativistic stellar equilibrium configurations in terms of functions that do not depend on the specific equation of state employed to describe matter at nuclear densities. These functions are normally referred to as "universal relations" and have been found to apply, within limits, both to static or stationary isolated stars, as well as to fully dynamical and merging binary systems. Further extending the idea that universal relations can be valid also away from stability, we show that a universal relation is exhibited also by equilibrium solutions that are not stable. In particular, the mass of rotating configurations on the turning-point line shows a universal behaviour when expressed in terms of the normalised Keplerian angular momentum. In turn, this allows us to compute the maximum mass allowed by uniform rotation, M_{max}, simply in terms of the maximum mass of the nonrotating configuration, M_{TOV}, finding that M_{max} ~ (1.203 +- 0.022) M_{TOV} for all the equations of state we have considered. We further show that a universal relation can be found between the dimensionless moment of inertia and the stellar compactness. Although this relation is not surprising as it involves two quantities that have been shown to exhibit universal behaviour with other stellar properties, our parameterisation represents a refinement over a similar relation by Lattimer and Schutz (2005), where a different normalisation was used, and could provide an accurate tool to constrain the equation of state of nuclear matter when measurements of the moment of inertia become available.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/e7ebc22d4412d72b96bd3c47080b52d4ac5baa88

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Citations in the corpus

Observation of Gravitational Waves from the Coalescence of a 2.5–4.5 M ⊙ Compact Object and a Neutron Star (2024, background): “…collected in Biscoveanu et al. (2022) including the spin-dependent properties of neutron stars (Foucart et al. 2018; Cipol-letta et al. 2015; Breu & Rezzolla 2016; Most et al. 2020b) to constrain the remnant baryon mass outside the final black hole following GW230529, assuming it was…”
Using Gravitational-wave Observations and Quasi-universal Relations to Constrain the Maximum Mass of Neutron Stars (2017, methodology): “Interestingly, the value for the configuration with maximum mass is only weakly dependent on the underlying EOS, and we find η := Mb Mmax ' 1.171 , (4) with a standard deviation of σ = 6.8 × 10−3.”
Evidence for a maximum mass cut-off in the neutron star mass distribution and constraints on the equation of state (2017, background): “…than a few percent, and typically much less7 (Cook et al. 1994; Ster- 7 Even at the extreme, mass-shedding limit, the mass of a nonrotating maximum mass neutron stars increases at most by ∼ 20% due rotation (Breu & Rezzolla 2016), this value being smaller for lower mass stars (Cook et al. 1994).”
Stellar structure models in modified theories of gravity: Lessons and challenges (2019, background): “literature on realistic EOS in their work on I-Love-Q relations, see ﬁgure 1 of that work for a quick glance on the mass-radius relations of many of the most popularEOS. In addition,Breu and Rezzolla [220] report up to 28 diﬀerent EOS motivated by diﬀerent theoretical considerations that are compati”
Approximate Universal Relations for Neutron Stars and Quark Stars (2016, methodology): “he relative fractional dierence of the numerical data and the t. Observe that the maximum fractional dierence for the neutron star sequence is at most 9%, which is consistent with Breu and Rezzolla [86] but slightly larger than that found in Baubock et al. [75] and Staykov et al. [256] (due to the u”