Cosmological Constant Effects on the Properties of Mass Twin Compact Stars

Abstract

We present a systematic investigation of the cosmological constant effects in compact stars interiors in the framework of Einstein's gravity. Consideration of a cosmological constant Λ in compact stars is motivated by the mechanism of acceleration of the observable universe, where Λ is usually related to the dark energy. In particular, we consider compact star mass twins, hybrid neutron stars that populate both the second and third branch of the mass-radius diagram. For those models, the need of consideration of excluded volume effects in the equation of state, resulting from the finite size volume of nucleons, leads to a stiffening of matter causing compact stars to acquire higher mass and radius values. We demonstrate that certain values of the cosmological constant can also modify the compact star properties but in an opposite way. In addition, we find that the inclusion of Λ can have a similar effect to the existence of pasta phases at the hadron-quark interface. *

Compact Star Twins with a Dark Matter Core

“…The search for DM in NS has become feasible due to the birth of multimessenger astronomy and progress on the determination of the cold, dense matter EoS. The macroscopical properties of compact stars may be affected from quantities like the cosmological constant [36] or the presence of DM, the latter considered here. Observations of the effects of a strong phase transition on supernova explosions, compact stars, and their mergers [37] or of NS cooling as well as detection of associated cosmic rays [38], eccentric binary orbits [39], emissions from evolutionary stages [40], or the growth of black holes as DM in the interior of rotating [41], may allow for Each curve corresponds to a sequence of compact stars for the same parameters within our model which is characterized by the hadronic m 0 parameter.…”

Radiating stars and Riccati equations in higher dimensions

“…The inclusion of a cosmological constant can modify the features of certain types of stars. For example, in four dimensions, it was shown by Largani and Álvarez-Castillo [49] that different values of the cosmological constant affect the mass features of twin compact stars. Afifah and Sulaksono [50] showed, using numerical methods, that the value of the cosmological constant is inversely proportional to the mass of neutron stars.…”