Related papers: The compact star in the SU(3) sigma model
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 calculate the equation of state of strange quark matter and the interior structure of strange quark stars in a Dyson-Schwinger quark model within rainbow or Ball-Chiu vertex approximation. We emphasize constraints on the parameter space…
The existence of stars with masses up to $2 M_{\odot}$ and the hints of the existence of stars with radii smaller than $\sim 11$ km seem to require, at the same time, a stiff and a soft hadronic equation of state at large densities. We…
An extended chiral SU(3) model is applied to the description of dense, hot and strange hadronic matter. The degrees of freedom are the baryon octet and decuplet and the spin-0 and spin-1 meson multiplets. The parameters of the model are…
We investigate the question of the nature of compact stars, considering they may be neutron stars or hybrid stars containing a quark core, within the present constraints given by gravitational waves, radio-astronomy, X-ray emissions from…
We extract the equation of state of hot quark matter from a holographic 2+1 flavor QCD model, which could form the core of a stable compact star. By adding a thin hadron shell, a new type of hybrid star is constructed. With the temperature…
We predict from a survey of equations of state and observations of X-ray pulsations from SAX J1808.4-3658, that the upper limit of the mass of the compact star is 2.27 solar mass. The corresponding upper limit of the radius comes out to be…
Boson stars arise as solutions of a massive complex scalar field coupled to gravity. A variety of scalar potentials, giving rise to different types of boson stars, have been studied in the literature. Here we study instead the effect of…
Neutron stars are the most dense objects in the observable Universe and conventionally one uses nuclear theory to obtain the equation of state (EOS) of dense hadronic matter and the global properties of these stars. In this work, we review…
The possibility of new short-distance physics applicable inside the cores of NS is incorporated into the equation of state generated by the quark-meson coupling model. The contribution of this new physics to the energy density is taken to…
Chiral effective theory has become a powerful tool for studying the low-energy properties of QCD. In this work, we apply an extended chiral effective theory -- chiral-scale effective theory -- including a dilatonic scalar meson to study…
The equation of state provided by effective models of strongly interacting matter should comply with the restrictions imposed by current astrophysical observations on compact stars. Using the equation of state given by the (axial-)vector…
The observation of $1.97\pm0.04$ solar-mass neutron-like star gives constraint on the equation of state (EOS) of cold, condensed matter. In this paper, the EOS for both pure quark star and hybrid star with a quark core described by…
The mass-radius relation of compact stars is discussed with relation to the presence of quark matter in the core. The existence of a new family of compact stars with quark matter besides white dwarfs and ordinary neutron stars is outlined.
We investigate the internal structure and the mass-radius relation of neutron stars in a recently proposed scalar-tensor theory dubbed asymmetron in which a massive scalar field undergoes spontaneous scalarization inside neutron stars. We…
The properties of neutron stars constituted of a crust of hadrons and an internal part of hadrons and kaon condensate are calculated within the quark-meson-coupling model. We have considered stars with nucleons only in the hadron phase and…
In this work we study the parameters of the extended $\sigma$-$\omega$ model for neutron star matter by a Bayesian analysis on state-of-the-art multi-messenger astronomy observations, namely mass, radius and tidal deformabilities. We have…
We present two types of models for hybrid compact stars composed of a quark core and a hadronic mantle with an abrupt first order phase transition at the interface which are in accordance with the latest astrophysical measurements of two 2…
We derive an equation of state for magnetized charge neutral nuclear matter relevant for neutron star structure. The calculations are performed within an effective chiral model based on generalization of sigma model with nonlinear self…
The measurement of the mass 1.97 +/- 0.04 M_sun for PSR J1614-2230 provides a new constraint on the equation of state and composition of matter at high densities. In this contribution we investigate the possibility that the dense cores of…