Related papers: Hybrid star properties from an extended linear sig…
We report on a three--month research project for undergraduate students about the mass-radius relation of compact stars. The equation of state used is constrained at low densities by well-established equations of state of the nuclear phase…
Recent observational data suggests a high compacticity (the quotient M/R) of some "neutron" stars. Motivated by these works we revisit models based on quark-diquark degrees of freedom and address the question of whether that matter is…
The effect of strong magnetic fields on the equation of state (EoS) for compact stars described with density-dependent relativistic hadronic models is studied. A comparison with other mean-field relativistic models is done. It is shown that…
The equation of state for quark matter is derived for a nonlocal, chiral quark model within the mean field approximation. Special emphasis is on the occurrence of a diquark condensate which signals a phase transition to color…
A compact star with superconducting quark core, the hadron crust and the mixed phase between the two is considered. The quark meson coupling model for hadron matter and the color flavor locked quark model for quark matter is used in order…
In this chapter we will introduce an effective equation of state (EoS) model based on polytropes that serves to study the so called "mass twins" scenario, where two compact stars have approximately the same mass but (significant for…
In this work, we consider the properties of compact stars in which quark matter has low- and high-density phases that are separated by a first-order phase transition. Thus, unlike the commonly considered case of a single phase transition…
We investigate the hadron-quark phase transition inside neutron stars and obtain mass-radius relations for hybrid stars. The equation of state for the quark phase using the standard NJL model is too soft leading to an unstable star and…
In this work, we perform a comparative analysis between the density-dependent quark model and the vector MIT bag model using Bayesian analysis. We use the equations of state generated by these two models to describe quark stars. We impose…
The properties of hadron-quark hybrid stars are studied when the quark phase is described in terms of a local SU(3) Nambu--Jona-Lasinio (NJL) model taking into account the contribution of the vector and axial-vector interaction between the…
A hybrid equation of state for dense matter is presented that satisfies phenomenological constraints from modern compact star observations which indicate high maximum masses of about 2 M_sun and large radii of R> 12 km. The corresponding…
Using a density dependent quark model and a relativistic model within the mean-field approximation for hadrons with density dependent meson-baryon couplings, we construct, for the first time, models that describe hybrid neutron stars…
Aims: We present a new microscopic hadron-quark hybrid equation of state model for astrophysical applications, from which compact hybrid star configurations are constructed. These are composed of a quark core and a hadronic shell with a…
We use a modified SU(2) chiral sigma model to study nuclear matter at high density using mean field approach. We also study the phase transition of nuclear matter to quark matter in the interior of highly dense neutron stars. Stable…
The exact composition of a specific class of compact stars, historically referred to as "neutron stars", is still quite unknown. Possibilities ranging from hadronic to quark degrees of freedom, including self-bound versions of the latter…
We study the properties of hybrid stars containing a color superconducting quark matter phase in their cores, which is described by the chirally symmetric formulation of the confining relativistic density functional approach. It is shown…
We study the impact of the fermion vacuum term in the SU(3) quark meson model on the equation of state and determine the vacuum parameters for various sigma meson masses. We examine its influence on the equation of state and on the…
We develop our previous study of the transition to deconfined quark phase in neutron stars, including the interaction in the quark equation of state to the leading order in the perturbative expansion within the confinement density-dependent…
We study quark-hadron hybrid stars with sharp phase transitions assuming that phase conversions at the interface are slow. Hadronic matter is described by a set of equations of state (EoS) based on the chiral effective field theory and…
Compact stars (CS) are stellar remnants of massive stars. Inside CSs the density is so high that matter is in subatomic form composed of nucleons. With increase of density of matter towards the centre of the objects other degrees of freedom…