Related papers: Constraints on temporal variation of fundamental c…
The phase diagram of a system constituted of neutrons and $\Lambda$-hyperons in thermal equilibrium is evaluated in the mean-field approximation. It is shown that this simple system exhibits a complex phase diagram with first and second…
In nucleus-nucleus collisions at ultra-relativistic energies matter is formed with initial energy density significantly exceeding the critical energy density for the transition from hadronic to partonic matter. We will review the…
We derive the bulk viscous time scale of neutron stars with quark matter core, i.e. hybrid stars. The r-mode instability windows of the stars show the theoretical result accords with the rapid rotation pulsar data. The fit gives a strong…
We argue that the full conversion of a hadronic star into a quark or a hybrid star occurs within two different regimes separated by a critical value of the density of the hadronic phase $\overline{n_h}$. The first stage, occurring for…
In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their outstanding macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…
It is currently unknown if neutron stars (NSs) are composed of nucleons only or are hybrid stars, i.e., in addition to nucleonic crusts and outer cores, they also possess quark cores. Quantum chromodynamics allows for such a possibility,…
Ever since the discovery of neutron stars it has been realized that they serve as probes of a physical regime that cannot be accessed in laboratories: strongly degenerate matter at several times nuclear saturation density. Existing nuclear…
Along with compacting baryon (neutron) spacing in a neutron star (NS), two very important factors come into play side by side: the lack of the NS gravitational self-stabilization against shutting to black hole (BH) and the phase transition…
We show that if color superconducting quark matter forms in hybrid or quark stars it is possible to satisfy most of recent observational boundaries on masses and radii of compact stellar objects. An energy of the order of $10^{53}$ erg is…
The existence of stars with a large mass of 2 solar masses means that the equation of state is stiff enough to provide high enough pressure at large central densities. Previous work shows that such a stiff equation of state is possible if…
We investigate the possibility of kaon condensation in the dense interior of neutron stars through the s--wave interaction of kaons with nucleons. We include nucleon--nucleon interactions by using simple parametrizations of realistic…
Some recent developments concerning the role of strange quark matter for astrophysical systems and the QCD phase transition in the early universe are addressed. Causality constraints of the soft nuclear equation of state as extracted from…
The properties of dense QCD matter are delineated through the construction of equations of state which should be consistent with the low and high density limits of QCD, nuclear laboratory experiments, and the neutron star observations.…
As we go from center toward the surface of a neutron star, the state of baryonic matter changes from the de-confined quark-gluon to a mixed phase of quark and hadronic matter, and a thin crust of hadronic matter. For the quark matter,…
We discuss cold dense QCD by examining constraints from neutron stars, nuclear experiments, and QCD calculations at low and high baryon density. The two solar mass constraint and suggestive small radii (10~13 km) of neutron stars constrain…
(Abridged) Neutron stars (NSs), the densest known objects composed of matter, provide a unique laboratory to probe whether strange quark matter is the true ground state of matter. We investigate the parameter space of the equation of state…
After a brief non technical introduction of the basic properties of strange quark matter (SQM) in compact stars, we consider some of the late important advances in the field, and discuss some recent astrophysical observational data that…
The phase-transition induced collapse of a neutron star to a more compact configuration (typically a ``strange'' star) and the subsequent core bounce is often invoked as a model for gamma-ray bursts. We present the results of numerical…
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…
We perform an O(alpha_s^2) perturbative calculation of the equation of state of cold but dense QCD matter with two massless and one massive quark flavor, finding that perturbation theory converges reasonably well for quark chemical…