Anisotropic neutron stars and perfect fluid’s energy conditions

Abstract

Abstract It is reported (Estevez-Delgado and Estevez-Delgado in Eur Phys J C 78:673, 2018) recently, that the absence of anisotropic in compact object pressure leads to a solution which is not physically acceptable due to the energy density and speed of sound can not be positive at the origin at the same time. Here, we calculate the pressure and energy density of NSs using realistic EOS predicted by a relativistic mean-field model including hyperons for isotropic and three different anisotropic pressure models such as the one of Doneva and Yazadjiev (Phys Rev D 85:124023, 2012), the one of Herrera and Barreto (Phys Rev D 88:084022, 2013), and the one of Bowers and Liang (Astrophys J 188:657, 1974). We obtain that the all of energy conditions of perfect fluid are satisfied not only by anisotropic NSs profiles but also the one of isotropic NSs.