Related papers: GW190814: Circumstantial Evidence for Up-Down Quar…
Using the parity doublet model (PDM) for hadronic matter and a modified Nambu-Jona-Lasinio (NJL) model for quark matter, we investigate the potential existence of two- and three-flavor quark matter in neutron star cores. Both models respect…
A recent analysis of photospheric radius expansion X-ray bursts from the low-mass X-ray binary 4U 1746-37 reported unusually small mass and radius estimates for the neutron star, suggesting it could be a quark star or quark-cluster star.…
Neutron stars (NSs) which could contain exotic degrees of freedom in the core and the self-bound quark stars (QSs) made purely of absolutely stable deconfined quark matter are still two main candidates for the compact objects observed in…
We introduce a new, powerful method to constrain properties of neutron stars (NSs). We show that the total mass of GW170817 provides a reliable constraint on the stellar radius if the merger did not result in a prompt collapse as suggested…
We study the effect of a magnetic field on the interacting quark matter and apply to strange star. We considere the low temperature approximation to strange matter. We find that the interacting strange quark matter is more stable compare to…
This study explores the properties of quark stars (QS) formulated with an interacting quark matter equation of state (EoS) within the framework of Rastall gravity, a modified theory of gravity. We derive the mass-radius relationships and…
We study the dimensionless spin parameter $j (= c J/ (G M^2))$ of uniformly rotating neutron stars and quark stars in general relativity. We show numerically that the maximum value of the spin parameter of a neutron star rotating at the…
The chemical evolution of nascent quark matter core in a newborn compact neutron star is studied in presence of a strong magnetic field. The effective rate of strange quark production in degenerate quark matter core in presence of strong…
We investigate the structure of quark stars in the framework of $f(R)= R+ \alpha R^2$ gravity using an equation of state for cold quark matter obtained from perturbative QCD, parametrized only by the renormalization scale. We show that a…
We study the effects of heavy quarks on the equation of state for cold and dense quark matter obtained from perturbative QCD, yielding observables parametrized only by the renormalization scale. We investigate the thermodynamics of charm…
The structure of a spherically symmetric stable dark 'star' is discussed, at zero temperature, containing 1) a core of quarks in the deconfined phase and antileptons 2) a shell of hadrons in particular $n$, $p$, $\Lambda$ and $\Sigma^-$ and…
The GW190814 event, involving a black hole of mass $22.2$--$24.3 M_{\odot}$ and a compact object of mass $2.50$--$2.67 M_{\odot}$, challenges our understanding of the mass gap between the heaviest neutron stars and the lightest black holes.…
In the past few years, new observations of neutron stars and neutron-star mergers have provided a wealth of data that allow one to constrain the equation of state of nuclear matter at densities above nuclear saturation density. However,…
Massive neutron stars (NS) are expected to possess a quark core. While the hadronic side of the NS equation of state (EOS) can be considered well established, the quark side is quite uncertain. While calculating the EOS of hadronic matter…
In an early work, we applied a QCD-based equation of state to the study of the stellar structure of self-bound strange stars, obtaining sequences with maximum masses larger than two solar masses and radii ranging from 8 to 12 Km. In this…
The secondary component of GW190814 with a mass of 2.50-2.67 $M_{\odot}$ may be the lightest black hole or the heaviest neutron star ever observed in a binary compact object system. To explore the possible equation of state (EOS), which can…
Quark matter is expected to exist in the interior of compact stellar objects as neutron stars or even the more exotic strange stars, based on the Bodmer-Witten conjecture. Bare strange quark stars and (normal) strange quark-matter stars,…
We present the results of the lattice QCD calculation of the average up-down and strange quark masses and of the light meson pseudoscalar decay constants, recently performed with Nf=2 dynamical fermions by the ETM Collaboration. The…
A fully non-perturbative lattice determination of the up/down and strange quark masses is given for quenched QCD using both, $O(a)$ improved Wilson fermions and ordinary Wilson fermions. For the strange quark mass with $O(a)$ improved…
Combining the GW observations of merging systems of binary neutron stars and quasi-universal relations, we set constraints on the maximum mass that can be attained by nonrotating stellar models of neutron stars. More specifically,…