Electrically charged white dwarfs in 4D Einstein-Gauss-Bonnet gravity

Abstract

As compact relativistic objects, white dwarfs are in different classes than neutron stars. Because white dwarfs are comparatively less compact than neutron stars are, the equation of state of a white dwarf is comparatively more certain. In this work, we investigated the basic properties of nonrotating white dwarfs composed of charged perfect fluid in the context of 4D Einstein-Gauss-Bonnet gravity. For example, we derived the mass, radius, energy density, pressure, charge distribution, and electric field of white dwarfs and demonstrated their dependency on the Gauss-Bonnet coupling constant \(\alpha \) in terms of the effect of charge. The structural solutions of white dwarfs are obtained by adopting Chandrasekhar’s equation of state and a significant relationship between charged density and energy density. In this context, we solve the TOV equation with the addition of the charge profile numerically by considering appropriate boundary conditions at the center of the star. By adjusting different parameters, we present a detailed graphical discussion of several characteristics of white dwarfs. We emphasize the mass-radius relationship of our proposed white dwarfs and compare the results with the Chandrasekhar mass limit for viable white dwarf structures. Moreover, the nature of the sound speed profile and adiabatic index in the internal structure of white dwarfs are discussed. As a result, we obtain a physically viable charged white dwarf structure with a mass near the Chandrasekhar mass limit in the context of the Einstein-Gauss-Bonnet gravity.