Aspects of rotating anisotropic dark energy stars

Abstract

By employing modified Chaplygin fluid prescription for the dark energy, we construct slowly rotating isotropic and anisotropic dark energy stars. The slow rotation is incorporated via general relativistic Hartle–Thorne formalism; whereas the anisotropy is introduced through Bowers–Liang prescription. We consider both the monopole and quadrupole deformations and present a complete analysis of rotating dark energy stars. By numerically solving the rotating stellar structure equations in presence of anisotropy, we analyse and quantify various properties of dark energy stars such as mass (M), radius, mass deformation, angular momentum (J), moment of inertia, and quadrupole moment (Q), for three different equation of state parameters. We find that anisotropic slow rotation results in significant deformation of stellar mass and thereby affects other global properties studied. For the values of angular frequencies considered, the effect of anisotropy on the stellar structure is found to be more prominent than that due to rotation. The dimensionless quadrupole moment QM/J2 measuring deviation from a Kerr metric black hole was obtained for anisotropic dark energy stars. We observe that dark energy stars with higher anisotropic strength tend to approach the Kerr solution more closely. We report that our results have considerable agreement with various astrophysical observational measurements. We also find that the dimensionless quadrupole moments of anisotropic dark energy stars corresponding to the canonical mass q¯1.4 have a similar range of values as that of isotropic neutron stars and strange stars.