Mass-Radius Relation of Strongly Magnetized White Dwarfs: Dependence on Field Geometry, GR effects and Electrostatic Corrections to the EOS

TL;DR

This paper investigates how general relativity, magnetic field geometry, and electrostatic corrections influence the mass-radius relation and maximum mass of strongly magnetized white dwarfs, with implications for supernovae.

Contribution

It extends previous Newtonian models by including GR effects and electrostatic corrections, and explores different magnetic field geometries to determine their impact on white dwarf mass limits.

Findings

GR effects reduce maximum mass by ~2%

Many-body corrections add another ~2% reduction

Toroidal and mixed magnetic fields can significantly increase mass limits

Abstract

Recent literature has seen an ongoing discussion on the limiting mass of strongly magnetized white dwarfs, since such objects may prove to be a source of over-luminous type-Ia supernovae. In an earlier paper, we have presented the mass-radius relation of white dwarfs with a strong poloidal magnetic field in Newtonian gravity. The inclusion of effects such as general relativistic gravity and many-body corrections to the equation of state can alter the mass-radius relation and the maximum mass. In this work we estimate the extent to which these effects may modify the earlier results. We find that the general relativistic effects tend to reduce the maximum mass by about 2% and many-body corrections by another additional $\sim$2%, for an assumed carbon composition. We also explore field geometries that are purely toroidal or a mixture of poloidal and toroidal and find that the limiting mass of such equilibrium configurations can be substantially higher than in the case of a purely poloidal field.