The existence of Quintessence star models in the lower mass gap within 5D Einstein–Gauss–Bonnet gravity

Abstract

Compact stellar objects, in particular, quintessence stars with an interior in which radial pressure is directly related to energy density through a linear equation, are obtained in 5-dimensional Einstein–Gauss–Bonnet (EGB) gravity in this article. For solving the gravitational field equations with the addition of an extra quintessence field identified by the equation of state (EoS) parameter wq with −1<wq<−1/3, we use the Krori–Barua ansatz for the metric potentials. In order to discuss the physical analysis of the resulting configuration, we settle the model parameters by utilizing the smooth connection between the interior spherical metric and the exterior Boulware–Deser metric. We have discussed the impact of EGB parameter α on different parameters of the stellar model with the help of three-dimensional plots for a wide range of α. We vary the EGB parameter α to produce the observed masses and radii of compact objects in order to check the physical reliability of the model. Corresponding to the large values of the parameter α, the current model replicates the mass of the neutron star J0740+6620, PSR J0952-0607, the massive unseen companion of 2MASS J05215658, and the secondary component of GW 190814 event detected by the experiment of Ligo/Virgo. The last two compact objects lie in the lower “mass Gap” (2.5−5)M⊙. The study of mass–radius relationships suggests that massive pulsars exist with standard radii in the range of (10–12) Km. and maximum masses consistent with the observational data. Thus, our findings provide circumstantial evidence for super-massive quintessence in 5D EGB gravity.