Strange quark mass(ms)dependent model of anisotropic strange quark star

This article presents the configuration of strange quark stars in hydrostatic equilibrium considering the Vaidya-Tikekar metric ansatz.The interior of such stars comprises strange quark matter(henceforth SQM),whose equation of state(hencefor orth EoS)is described by the MIT EoS p=1/3(p-4B),where B is the difference between perturbative and non-perturbative vacuum.We have included the mass of the strange quark into the EoS and studied its effect on the overall properties of the strange quark star in this work.It is observed that the maximum mass reaches its highest value when.We have evaluated the range of the maximum mass of the strange quark star by solving the TOV equation for 57.55<B<91.54 MeV/fm^(3)necessary for stable strange quark matter at a zero external pressure condition with respect to neutrons.Maximum mass lies within the range of to when B ranges from 57.55 to 91.54MeV/fm^(3)and ms=0.It is noted that the maximum mass decreases with an increase in.Our model is found suitable for describing the mass of pulsars such as PSR J1614-2230 and Vela X-1 and the secondary objects in the GW170817 event.The model is also useful in predicting the radius of the recently observed pulsars PSR J0030+0451,PSR J0740+6620,and PSR J0952-0607 and the secondary objects in the GW170817 and GW190814 events.Our model is found to be stable with respect to all stability criteria of the stellar configurations and is also stable with respect to small perturbations.

Maximum mass of anisotropic charged strange quark stars in a higher dimensional approach(D≥4)

In this article,a new class of solutions of Einstein-Maxwell field equations of relativistic strange quark stars obtained in dimensions D≥4,is shown.We assume that the geometry of space-time is pseudo-spheroid,embedded in Euclidean space of(D-1)dimensions.The MIT bag model equation of state(henceforth EoS)is employed to study the relevant properties of strange quark stars.For the causal and non-negative nature of the square of the radial sound velocity(vr2),we observe that some restrictions exist on the reduced radius(b/R),where R is a parameter related to the curvature of the space-time,and b is the radius of the star.The spheroidal parameter A used here defines the metric potential of the grrcomponent,which is pseudo-spheroidal in nature.We note that the pressure anisotropy and charge have some effects onλ.The maximum mass for a given surface density(ρs)or bag constant(B)assumes a maximum value in dimension D=5and decreases for other values of D.The generalized Buchdahl limit for a higher dimensional charged star is also obeyed in this model.We observe that in this model,we can predict the mass of a strange quark star using a suitable value of the electric charge(Q)and bag constant(B).Energy and stability conditions are also satisfied in this model.Stability is also studied considering the dependence of the Lagrangian perturbation of radial pressure(Δpr)on the frequency of normal modes of oscillations.The tidal Love number and tidal de-formability are also evaluated.

Strange Quark Matter and Strangelets in a Strong Magnetic Field

We study the stability properties of magnetized strange quark matter and strangelets under a strong magnetic field in the MIT bag model. The free energy per baryon of strange quark matter feels a great influence from the magnetic field. At the field strength about 1017 G, the magnetized strange quark matter becomes more stable.Considering the finite size effect, the magnetic influence on strangelets becomes complicated. For a given magnetic field, there exists a critical baryon number, below which the magnetized strangelets have lower energy than the nonmagnetized strangelets. For the field strength of 5 × 1017 G, the critical baryon number is Ac～ 100. Generally, the critical baryon number increases with the decreasing external magnetic field. When the field strength is smaller than1017 G, the critical baryon number goes up to Ac～ 105. The stable radius, electric charge, and quark flavor fractions of magnetized strangelets are shown.