On the mass of moderately rotating strange stars in the MIT bag model and LMXBs

We present the first fully relativistic numerical calculations of differentially rotating Strange Quark Stars models for broad ranges of the maximum density and of the degree of differential rotation. Our simulations are performed with the very accurate and stable multi-domain spectral code FlatStar and use the MIT Bag model for describing strange quark matter. Our calculations based on a thorough exploration of the solution space show that the maximum mass of strange stars d...

We compare the mass-radius relationship of strange stars obtained in two theoretical frameworks describing the color-flavor-locking state of dense quark matter: The semi-empirical MIT model and a self-consistent approach using the Nambu-Jona-Lasinio (NJL) model. In the simplest MIT model extended to include pairing, one can make the equation of state stiffer by increasing the gap parameter so that larger maximum masses for these objects can be reached. In the NJL model, howev...

The quasiparticle model is extended to investigate the properties of strange quark matter in a strong magnetic field at finite densities. For the density-dependent quark mass, self-consistent thermodynamic treatment is obtained with an additional effective bag parameter, which depends not only on the density but also on the magnetic field strength. The magnetic field makes strange quark matter more stable energetically when the magnetic field strength is less than a critical ...

This study describes the impact of non-zero value of strange quark mass $(m_{s})$ and number density of baryons $(n)$ on the structure, stability and maximum mass of strange stars. We derive an exact relativistic solution of the Einstein field equation using the Tolman-IV metric potential and modified MIT bag model EoS, $p_{r}=\frac{1}{3}(\rho-4B')$, where $B'$ is a function of bag constant $B$, $m_{s}$ and baryon number density $(n)$. Following CERN's findings, transition of...

We propose a spherically symmetric and anisotropic model for strange quark stars within the framework of MIT Bag model. Though the model is found to comply with all the physical requirements of a realistic star satisfying a strange matter equation of state (EOS), the estimated values the Bag constant for different strange star candidates like Her X-1, SAX J 1808.4-3658 and 4U 1820-30, clearly indicate that the Bag constant need not necessarily lie within the range of 60-80 Me...

In this article we have calculated the structure properties of a strange quark star in static model in the presence of a strong magnetic field using MIT bag model with a density dependent bag constant. To parameterize the density dependence of bag constant, we have used our results for the lowest order constrained variational calculation of the asymmetric nuclear matter. By calculating the equation of state of strange quark matter, we have shown that the pressure of this syst...

We have discussed dynamical behavior of strange quark matter components, in particular the effects of density dependent quark mass on the equation of state of strange quark matter. Dynamical masses of quarks have been computed within Nambu-Jona-Lasinio (NJL) model, then we have done the strange quark matter calculations employing the MIT bag model with these dynamical masses. For the sake of comparing dynamical mass interaction with QCD quark-quark interaction, we have consid...

In this paper, we investigate the newborn strange quark stars with constant entropy. We also use the MIT bag model to calculate the thermodynamic properties in two cases; the density-dependent bag constant and the fixed bag constant (B = 90 MeV). We show that the equation of state becomes stiffer by using the density dependent bag constant and by increasing the entropy. Furthermore, we show that the adiabatic index of the system reaches to 4/3 at high densities. Later, we cal...

In this article we propose a new class of isotropic strange star using Buchdahl-I metric ansatz and MIT bag model equation of state in presence of non-zero strange quark mass $(m_{s})$ in the framework of modified $f(R,T)$ theory of gravity. The barotropic form of MIT bag model equation of state and a specific class of $f(R,T)$ model {\it viz.}, $f(R,T)=R+2\alpha_{c}T$ where $\alpha_{c}$ is termed as the gravity-matter coupling constant, produces a tractable set of solutions ...

Exact calculations of innermost stable circular orbit (ISCO) around rotating strange stars are performed within the framework of general relativity. Equations of state (EOS) of strange quark matter based on the MIT Bag Model with massive strange quarks and lowest order QCD interactions, are used. The presence of a solid crust of normal matter on rotating, mass accreting strange stars in LMXBs is taken into account. It is found that, contrary to neutron stars, above some minim...