A superdense star model as charged analogue of Schwarzschild?s interior solution

Abstract

A charged analogue of Schwarzschild's interior solution has been derived by considering the non-gravitational energy density to be constant along with a special choice of electric intensity. The charged fluid sphere so obtained is seen to be more general than that of P.S. Florides and joins smoothly with the Reissner-Nordström metric at the pressure-free interface. Also the new charged fluid sphere is capable of representing a superdense star with surface density of 2 × 10 14 g cm −3 which can occupy maximum mass 1.502408 times the solar mass. In the process of deriving the solution, the authors have also come across A. L. Mehra's gaseous charged fluid model which is found to be unphysical as it has negative pressure at least at the center of the model.

Some new Wyman–Leibovitz–Adler type static relativistic charged anisotropic fluid spheres compatible to self-bound stellar modeling

“…Known applicable analytic solutions include [4,5,22]: In contrast, as far the literature is concerned known to the present authors, the charged analogs of Tolman's models (V-VI) obtained in [95][96][97][98][99][100][101] are not physically viable in the description of compact astrophysical objects as regards the infinite values of the central density and pressure. Though the Schwarzschild constant density solution is physically unrealistic, the charged analogs, obtained in [56,[102][103][104], and the charged analog of the Matese and Whitman solution, obtained in [105], may be relevant in the description of self-bound electrically charged strange quark stars. Charged analogs of the Tolman IV and VII models [106][107][108]), as the neutral ones, exhibit the physical features required for the construction of a physically realizable relativistic compact stellar structure.…”

A new class of solutions of anisotropic charged distributions on pseudo-spheroidal spacetime

“…The study of charge distributions on spheroidal spacetimes have been carried out by Patel and Kopper (1987), Tikekar and Singh (1998), , Gupta and Kumar (2005), Komathiraj and Maharaj (2007). The spheroidal spacetime is found to accommodate superdense stars like neutron stars in both charged and uncharged cases.…”

Nonsingular charged analogues of Schwarzschild’s interior solution

“…A generalization procedure has been utilized to generalize solutions by Guilfoyle (1999). Recently found solutions by Gupta and Kumar (2005a, 2005b, 2005c are generalized by taking particular form of f and seen to have higher mass and more stable. The maximum mass is found to be 1.59482 M .…”

“…Among these the solutions of particular interest include the charge generalization of the incompressible Schwarzschild interior spheres i.e. with constant non-gravitational energy density (T 4 4 ) (Florides 1983;Guilfoyle 1999;Gupta and Kumar 2005a) and gaseous model Mehra (1980) which is later found unphysical (Gupta and Kumar 2005a) on account of the presence of negative pressure. All the solutions mentioned above are reducible to Schwarzschild interior solution in the absence of charge.…”

“…All solutions by Guilfoyle (1999) are generalized. One of the models is a generalization of that by Gupta and Kumar (2005a) which itself was more general than that of Florides (1983) and joins smoothly with the Reissner-Nordstrom metric at the pressure free interface 'r = a'. The solution is further utilized to represent a model of charged superdense star with ultrahigh surface density of the order 2 × 10 14 gm cm −3 .…”