Neutron star deformability with hyperonization in density dependent relativistic mean-field models

Neutron star tidal deformability extracted from gravitational wave data provides a novel probe to the interior neutron star structures and the associated nuclear equation of state (EOS). Instead of the popular composition of nucleons and leptons in neutron stars, we include hyperons and examine the role of hyperons in the tidal deformability and its impact on the symmetry energy in a relativistic mean-field approach with the density-dependent parametrizations. The hyperons are found to have a significant impact on the deformability, correlated sensitively with the onset density and fraction of hyperons in neutron star matter. A moderately lower onset density of hyperons can yield considerable modification to the tidal deformability and shift its inference on the nuclear EOS. The future measurements of the tidal deformability at multifiducial star masses are anticipated to lift the degeneracy between the contributions from the hyperon component and symmetry energy.

Automated summary

The study shows that hyperons have a significant impact on the tidal deformability of neutron stars, and lower onset density of hyperons can considerably modify the deformability and affect the inference on the nuclear EOS.