Mass of highly magnetized white dwarfs exceeding the Chandrasekhar limit: An analytical view

TL;DR

This paper analytically investigates how extremely strong magnetic fields influence the stability and mass-radius relation of white dwarfs, revealing the possibility of white dwarfs exceeding the Chandrasekhar mass limit.

Contribution

It provides an analytical study of the effects of high magnetic fields on the equation of state and stability of white dwarfs, showing they can surpass the Chandrasekhar limit.

Findings

White dwarfs can have masses exceeding the Chandrasekhar limit due to strong magnetic fields.

Landau quantization significantly alters the equation of state in high magnetic fields.

The mass-radius relation is modified, allowing for more massive white dwarfs.

Abstract

In recent years a number of white dwarfs has been observed with very high surface magnetic fields. We can expect that the magnetic field in the core of these stars would be much higher (~ 10^{14} G). In this paper, we analytically study the effect of high magnetic field on relativistic cold electron, and hence its effect on the stability and the mass-radius relation of a magnetic white dwarf. In strong magnetic fields, the equation of state of the Fermi gas is modified and Landau quantization comes into play. For relatively very high magnetic fields (with respect to the energy density of matter) the number of Landau levels is restricted to one or two. We analyse the equation of states for magnetized electron degenerate gas analytically and attempt to understand the conditions in which transitions from the zero-th Landau level to first Landau level occur. We also find the effect of the strong magnetic field on the star collapsing to a white dwarf, and the mass-radius relation of the resulting star. We obtain an interesting theoretical result that it is possible to have white dwarfs with mass more than the mass set by Chandrasekhar limit.