White dwarfs in regularized 4D Einstein-Gauss-Bonnet gravity

Fuente: arXiv
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Autores principales: Pretel, Juan M. Z., Tangphati, Takol, Sakallı, İzzet, Banerjee, Ayan
Formato: Preprint
Publicado: 2025
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author Pretel, Juan M. Z.
Tangphati, Takol
Sakallı, İzzet
Banerjee, Ayan
author_facet Pretel, Juan M. Z.
Tangphati, Takol
Sakallı, İzzet
Banerjee, Ayan
contents White dwarfs (WDs), as the remnants of low to intermediate-mass stars, provide a unique opportunity to explore the interplay between quantum mechanical degeneracy pressure and gravitational forces under extreme conditions. In this study, we examine the structure and macroscopic properties of WDs within the framework of 4D Einstein-Gauss-Bonnet (4DEGB) gravity, a modified theory that incorporates higher-order curvature corrections through the Gauss-Bonnet coupling constant $α$. Using the modified Tolman-Oppenheimer-Volkoff (TOV) equations tailored for 4DEGB gravity, we analyze the hydrostatic equilibrium of WDs modeled with a realistic equation of state (EoS). Our findings reveal that the inclusion of the Gauss-Bonnet (GB) term significantly influences the mass-radius ($M-R$) relation, allowing for deviations from the Chandrasekhar mass limit. In particular, we observe that such stars become more compact and slightly smaller with the increase of the parameter $α$. For WDs with $\vertα\vert \leq 500\, \rm km^2$, the impact of 4DEGB gravity appears to be negligible. However, a larger range for $α$ allows for appreciable changes in the $M-R$ diagram, mainly in the high-central-density region. Furthermore, we explore the role of anisotropic pressures, quantified by the parameter $β$, on such systems and demonstrate their impact on stability and compactness. For sufficiently large values of $\vertβ\vert$ keeping negative $β$ with a large and positive $α$, there exists a second stable branch according to the classical stability criterion $dM/dρ_c >0$. These results suggest that anisotropic WDs in 4DEGB gravity exhibit unique characteristics that distinguish them from their general relativistic counterparts, offering a novel testing ground for modified gravity theories in astrophysical settings.
format Preprint
id arxiv_https___arxiv_org_abs_2505_08153
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle White dwarfs in regularized 4D Einstein-Gauss-Bonnet gravity
Pretel, Juan M. Z.
Tangphati, Takol
Sakallı, İzzet
Banerjee, Ayan
General Relativity and Quantum Cosmology
High Energy Astrophysical Phenomena
Solar and Stellar Astrophysics
White dwarfs (WDs), as the remnants of low to intermediate-mass stars, provide a unique opportunity to explore the interplay between quantum mechanical degeneracy pressure and gravitational forces under extreme conditions. In this study, we examine the structure and macroscopic properties of WDs within the framework of 4D Einstein-Gauss-Bonnet (4DEGB) gravity, a modified theory that incorporates higher-order curvature corrections through the Gauss-Bonnet coupling constant $α$. Using the modified Tolman-Oppenheimer-Volkoff (TOV) equations tailored for 4DEGB gravity, we analyze the hydrostatic equilibrium of WDs modeled with a realistic equation of state (EoS). Our findings reveal that the inclusion of the Gauss-Bonnet (GB) term significantly influences the mass-radius ($M-R$) relation, allowing for deviations from the Chandrasekhar mass limit. In particular, we observe that such stars become more compact and slightly smaller with the increase of the parameter $α$. For WDs with $\vertα\vert \leq 500\, \rm km^2$, the impact of 4DEGB gravity appears to be negligible. However, a larger range for $α$ allows for appreciable changes in the $M-R$ diagram, mainly in the high-central-density region. Furthermore, we explore the role of anisotropic pressures, quantified by the parameter $β$, on such systems and demonstrate their impact on stability and compactness. For sufficiently large values of $\vertβ\vert$ keeping negative $β$ with a large and positive $α$, there exists a second stable branch according to the classical stability criterion $dM/dρ_c >0$. These results suggest that anisotropic WDs in 4DEGB gravity exhibit unique characteristics that distinguish them from their general relativistic counterparts, offering a novel testing ground for modified gravity theories in astrophysical settings.
title White dwarfs in regularized 4D Einstein-Gauss-Bonnet gravity
topic General Relativity and Quantum Cosmology
High Energy Astrophysical Phenomena
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2505.08153