An introductory study to white dwarfs

TL;DR

This paper provides an introductory analysis of white dwarfs using different equations of state and gravitational models, exploring stability and rotation effects through theoretical and numerical methods.

Contribution

It introduces a comparative study of white dwarf models with Newtonian and relativistic gravity, including rotation and stability analysis using the RNS numerical code.

Findings

Relativistic effects influence white dwarf stability.

Rotation impacts the mass and structure of white dwarfs.

The turning point criterion helps identify instability regions.

Abstract

White dwarfs are compact objects that stand against gravitational collapse by their internal pressure of degenerate matter. In this work we aimed to perform an introductory study on these stars, using two equations of state (EOS): (I) an ideal Fermi gas and (II) the one by Baym Pethick and Sutherland (BPS). In addition, we analyzed these two equations of state in two scenarios, the Newtonian and the one from General Relativity, which allowed us to analyze the effects of curved space-time. We also studied a rotating white dwarf, finding a metric for this case. With these two cases, with rotation (J = cte) and static (J = 0) well determined, we introduced the concepts of instability by the turning point criterion and dynamic instability criterion. Finally, with the RNS program, we performed the numerical resolution with BPS equation of state in the rotating case in order to analyze the behavior of the turning point criterion in these two cases.