Causal Representations of Neutron-Star Equations of State

TL;DR

This paper introduces new parameterizations for neutron-star equations of state that can accurately represent any model while ensuring causality and stability, improving the analysis of astronomical data.

Contribution

The paper presents novel parameterizations that can represent any neutron-star equation of state with high accuracy and automatically enforce physical constraints.

Findings

New parameterizations accurately represent diverse equations of state.

The methods automatically impose causality and thermodynamic stability.

Numerical tests demonstrate high efficiency and precision.

Abstract

Parameterized representations of the equation of state play an important role in efforts to measure the properties of the matter in the cores of neutron stars using astronomical observations. New representations are presented here that are capable of representing any equation of state to any desired level of accuracy, while automatically imposing causality and thermodynamic stability constraints. Numerical tests are presented that measure how accurately and efficiently these new parameterizations represent a collection of causal nuclear-theory model equations of state.