Quarkyonic Neutron Stars as Candidates for the GW230529 Mass-Gap Object

TL;DR

This paper investigates whether quarkyonic matter equations of state can explain the existence of compact objects in the 2.5-4.5 solar mass range, potentially filling the mass gap observed in gravitational wave event GW230529.

Contribution

It demonstrates that quarkyonic EOS models can produce stable neutron star configurations within the mass gap, challenging the black hole interpretation.

Findings

Quarkyonic EOS models allow stable stars above 2.5 solar masses.

Predicted radii are approximately 13-15 km for these massive stars.

The results suggest the GW230529 object could be a quarkyonic neutron star.

Abstract

We examine whether quarkyonic equations of state (EOS) can account for compact objects in the $2.5$-$4.5\,M_\odot$ mass range reported for the GW230529 gravitational-wave event. The pressure-energy density and mass-radius (M-R) relations obtained from quarkyonic EOS models indicate a significant stiffening at high densities, allowing stable configurations beyond $2.5\,M_\odot$. The predicted M-R sequences extend into the GW230529 mass window while maintaining radii in the range of $\approx 13$-$15$~km, suggesting that quarkyonic stars can naturally populate the so-called compact object mass gap. These results imply that the heavier component of GW230529 could plausibly be a massive quarkyonic neutron star rather than a low-mass black hole.