Relaxational effects in radiating stellar collapse

TL;DR

This paper investigates how relaxational effects influence heat transport in radiating stellar collapse, demonstrating that causal relativistic thermodynamics predicts significant temperature increases and gradients, confirmed by a non-perturbative stellar model.

Contribution

It introduces a non-perturbative stellar model that incorporates relaxational effects, extending previous perturbative analyses in relativistic heat transport.

Findings

Relaxational effects significantly increase central temperature.

Temperature gradients are notably affected by relaxational dynamics.

Non-perturbative model confirms perturbative predictions qualitatively.

Abstract

Relaxational effects in stellar heat transport can in many cases be significant. Relativistic Fourier-Eckart theory is inherently quasi-stationary, and cannot incorporate these effects. The effects are naturally accounted for in causal relativistic thermodynamics, which provides an improved approximation to kinetic theory. Recent results, based on perturbations of a static star, show that relaxation effects can produce a significant increase in the central temperature and temperature gradient for a given luminosity. We use a simple stellar model that allows for non-perturbative deviations from staticity, and confirms qualitatively the predictions of the perturbative models.