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Stellar properties indicating the presence of hyperons in neutron stars

Andreas Bauswein1,2, Aristeidis Nikolaidis1,3, Georgios Lioutas4, Hristijan Kochankovski5, Prasanta Char6,7, Chiranjib Mondal8, Micaela Oertel9,10, Laura Tolos11,12, Nicolas Chamel8 et al.

Stephane Goriely8

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Phys. Rev. Research 8, 013253 – Published 6 March, 2026

DOI: https://doi.org/10.1103/ygtr-ktqk

Abstract

We describe distinctive stellar features indicating the presence of hyperons in neutron stars as compared to purely nucleonic systems. A strongly negative curvature of the mass-radius relation R(M) is characteristic of hyperons, which can be determined from measurements of neutron stars with three different masses. Similarly, a reduced second derivative of the tidal deformability as a function of mass λ(M) points to hyperonic degrees of freedom in neutron star matter. The slopes of such curves R(M) and λ(M) can distinguish a hyperonic equation of state from purely nucleonic models if they appear increased [decreased for λ(M)] relative to the maximum mass of neutron stars.

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Phys. Rev. Research 8, 013253– Published 6 March, 2026
  • Received 14 July 2025
  • Accepted 26 January 2026
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