White Dwarfs in General Relativity

Abstract

Stars with masses less than 10M⊙ culminate as white dwarfs, which represent the most prevalent category of compact stars. While they are less dense than other compact stars and can be described through Newtonian gravitation, a more precise depiction employs general relativity. Number of approaches have been employed to model white dwarf matter. In this thesis, we discuss a recently developed approach: the relativistic Feynman-Metropolis-Teller treatment, which encompasses and advances the previous methodologies. The equation of state takes into consideration β-equilibrium, Coulomb and nuclear interactions. Quantum statistics, electromagnetic, strong, and weak nuclear interactions are integrated via the cell’s chemical potential. The contribution of general relativistic equilibrium is also encapsulated by the formula µwseν(r)/2 = constt, where µws is chemical potential of the Wigner-Seitz cell and eν(r) is the general relativistic gravitational potential. Each cell maintains electrical neutrality, obviating the necessity for an electric field to sustain the equilibrium of the star. Moreover, the critical mass and mass-radius relationship are discussed for different compositions of the star