Orbital Ferromagnetism and the Chandrasekhar Mass-Limit

TL;DR

This paper investigates how Landau orbital ferromagnetism influences the stability and mass limits of relativistically degenerate compact stars, revealing critical parameters that govern their collapse and magnetic properties.

Contribution

It introduces a generalized magnetic equation of state for LOFER and analyzes its impact on the stability and mass limit of white dwarfs and neutron stars.

Findings

Magneto-gravitational stability depends on parameters s and β.

Critical value β_cr = √(2π) determines stability.

Parameters s and β influence collapse mechanisms and mass limits.

Abstract

In this paper, using both quantum magnetohydrodynamic (MHD) and magnetohydrostatic (MHS) models of a relativistically degenerate magnetic compact star, the fundamental role of Landau orbital ferromagnetism (LOFER) on the magneto-gravitational stability of such star is revealed. It is shown that the previously suggested magnetic equation of state for LOFER with some generalization of form $B=\beta \rho^{2s/3}$ only within the range $0\leq s\leq 1$ and $0\leq \beta< \sqrt{2\pi}$ leads to magneto-gravitational stability with distinct critical value $\beta_{cr}=\sqrt{2\pi}$ governing the magnetohydrostatic stability of the compact star. Furthermore, the value of the parameters $s$ and $\beta$ is shown to fundamentally control both the quantum and Chandrasekhar gravitational collapse mechanisms and the previously discovered mass-limit on white dwarfs. Current findings can help to understand the origin of magnetism and its inevitable role on the stability of the relativistically degenerate super-dense magnetized matter encountered in many white-dwarfs and neutron stars.