Related papers: P-Stars
We investigate compact objects formed by dark matter admixed with ordinary matter made of neutron star matter and white dwarf material. We consider non-self annihilating dark matter with an equation-of-state given by an interacting Fermi…
It is believed that pulsars are neutron stars or strange stars with crusts. However we suggest here that pulsars may be bare strange stars (i.e., strange stars without crust). Due to rapid rotation and strong emission, young strange stars…
Witten's conjecture about strange quark matter (`Strange Matter') being the ground state of QCD at finite baryon number is presented and stars made of strange matter (`Strange Stars') are compared to neutron stars. The only observable way…
Using the formalism of general relativity for axially symmetric gravitational fields and their sources - rotating compact stars - a perturbation theory with respect to angular velocity is developed and physical quantities such as mass,…
We study the cooling behaviour of an isolated strange quark star, using an equation of state derived from perturbative QCD up to second order in strong coupling constant, and we compare it with that of a neutron star. After an initial rapid…
Neutron stars with extremely high central energy density are natural laboratories to investigate the appearance and the properties of compactified extra dimensions with small compactification radius, if they exist. Using the same formalism,…
Based on the properties of uniform nuclear matter at the nuclear saturation density and basic thermodynamic relations, we first re-study the composition of matter on the surface of normal neutron stars and hybrid stars. It is found that the…
We propose a novel cosmological scenario in which baryonic neutron stars could plausibly form in the early universe. If baryogenesis initially produces an excessively-large baryon asymmetry, $Y_B \gg 10^{-10},$ the baryonic mass inside the…
We review the status of research on the cooling of compact stars, with emphasis on the influence of color superconducting quark matter phases. Although a consistent microscopic approach is not yet available, severe constraints on the phase…
Recent achievements of bare strange stars are briefly reviewed. A nascent protostrange star should be bare because of strong mass ejection and high temperature after the supernova detonation flame, and a crust can also hardly form except…
We present a short atlas illustrating the unusual Ca {\sc ii} K-line profiles in upper main sequence stars with anomalous abundances. Slopes of the profiles for 10 cool, magnetic chemically peculiar (CP) stars change abruptly at the very…
We show the possible existence of compact stars having a surface composed of a mixed phase of quarks and hadrons. This scenario can be realized both for self-bound stars, satisfying the so-called Witten-Bodmer hypothesis, and for…
Neutron stars -- compact objects with masses similar to that of our Sun but radii comparable to the size of a city -- contain the densest form of matter in the universe that can be probed in terrestrial laboratories as well as in earth- and…
We construct relativistic equilibrium models of differentially rotating neutron stars and show that they can support significantly more mass than their nonrotating or uniformly rotating counterparts. We dynamically evolve such…
The densest predicted state of matter is colour-superconducting quark matter, in which quarks near the Fermi surface form a condensate of Cooper pairs. This form of matter may well exist in the core of compact stars, and the search for…
Pop III stars are the first stars in the universe. They do not contain metals and their formation and evolution may be different from that of stars of later generations. In fact, according to the theory of star formation, Pop III stars…
We develop a theoretical framework to study slowly rotating compact stars in a rather general class of alternative theories of gravity, with the ultimate goal of investigating constraints on alternative theories from electromagnetic and…
Recently, observations of compact stars have provided new data of high accuracy which put strong constraints on the high-density behaviour of the equation of state of strongly interacting matter otherwise not accessible in terrestrial…
If the dark matter is composed of axions, then axion stars are expected to be abundant in the Universe. We demonstrate in fully non-linear (3+1) numerical relativity the instability of compact axion stars due to the electromagnetic…
There is accumulating evidence that (fundamental) scalar fields may exist in Nature. The gravitational collapse of such a boson cloud would lead to a boson star (BS) as a new type of a compact object. Similarly as for white dwarfs and…