Numerical Solutions and Stability Analysis of White Dwarfs with a Generalized Anisotropic Factor

Galaxies, 2025

Full text Open access: Gold Metadata (CSL-JSON)
DOI 10.3390/galaxies13030069
Data confidence 70 medium
How this score is calculated

It is built from checkable properties of the record itself: whether the article has a DOI, how many independent sources confirmed its data, whether the required fields are filled in, and how recent the latest confirmation is. Disagreement between sources and a missing identifier lower it. A value of 80 or above means the record was published without further checking; 60 to 79 means it is published at reduced confidence, with a manual check advisable. A record verified by an editor by hand is never pushed below 90 by a recalculation. This scores our data about the article, not the article itself.

Abstract

This study examines the equilibrium structure and stability of white dwarfs, incorporating both isotropic and anisotropic pressure distributions. The Tolman–Oppenheimer–Volkoff (TOV) equation is numerically solved using the Chandrasekhar equation of state (EoS) to analyze the effects of pressure anisotropy. A general anisotropy function is introduced to close and solve the system of differential equations. The results indicate that anisotropy remains negligible at the center and increases toward the stellar surface. Stability is assessed using the speed of sound criterion, vs2=dp/dρ, and the Buchdahl bound, 2M/R<8/9, confirming that white dwarfs remain within stability limits. We performed a sensitivity analysis to examine how variations in the anisotropy parameter α0 and central density affect the mass, radius, and compactness of white dwarfs. Additionally, we calculated the gravitational redshift at the stellar surface and found that it varies with anisotropy, ranging from zs∼3.15×10−3 in isotropic cases to zs∼0.2×10−3 in highly anisotropic models. These results link anisotropy to potentially observable features. The findings suggest that while anisotropy does not significantly affect the overall equilibrium structure, it may play a role in astrophysical scenarios involving strong magnetic fields, rotational deformations, or accretion processes in binary systems.