"Pseudo-Conformal" Sound Speed in the Core of Compact Stars

TL;DR

This paper argues that a pseudo-conformal symmetry influences the behavior of nuclear matter from low to high densities in neutron stars, linking scale invariance to observed properties like the sound speed and quenched axial coupling.

Contribution

It introduces the concept that pseudo-conformal symmetry governs nuclear interactions across densities, explaining the sound speed and axial coupling in neutron stars.

Findings

Sound speed in neutron stars approaches 1/3 of light speed.

Quenched g_A in nuclei is linked to scale invariance.

Quasi-baryons may mimic deconfined quarks in star cores.

Abstract

We present the argument that "pseudo-conformal" symmetry permeates from low density near nuclear matter to high density in the core of massive neutron stars. As a support of this argument, we describe how the quenched $g_A\approx 1$ in nuclei and the sound speed $v_s^2/c^2\approx 1/3$ in compact stars are controlled by emerging scale invariance in nuclear interactions. In our description, quasi-baryons could "masquerade" de-confined quarks in the interior of compact stars.