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In this article, we have discussed Morris and Thorne (MT) wormhole solutions in a modified theory of gravity that admits conformal motion. Here, we explore the wormhole solutions in f (R , T) gravity, which is a function of the Ricci scalar (R) and the trace of the stress–energy tensor (T). To study wormhole geometries, we make assumption of spherical symmetric static spacetime and the existence of conformal Killing symmetry to get more acceptable astrophysical outcomes. To do this, we choose the expression of f (R , T) as f (R , T) = R + 2 γ T. Here, we employ the phantom energy EoS relating to radial pressure and density given by p r = ω ρ with ω < − 1 to constrain our model. Following a discussion of wormhole geometry and behavior of shape function, the study moves on to the computation of proper radial distance, active mass function, the nature of total gravitational energy and a discussion on the violation of energy conditions. We have shown that the wormhole solutions exist for positive as well as negative values of the coupling constant γ. From our analysis, we see that no wormhole solution exists for γ = − 4 π , − π (3 + ω). All the physical parameters have been drawn by employing the values of γ as γ = − 0. 3 , − 0. 2 , − 0. 1 , 0 , 0. 1 and 0. 2 , where γ = 0 corresponds to general relativity (GR) case. It is found that for our proposed model, a realistic wormhole solution satisfying all the properties can be obtained. [ABSTRACT FROM AUTHOR]

In the present paper, we have constructed a new relativistic anisotropic compact star model having a spherically symmetric metric of embedding class one. Here we have assumed an arbitrary form of metric function and solved the Einstein's relativistic field equations with the help of Karmarkar condition for an anisotropic matter distribution. The physical properties of our model such as pressure, density, mass function, surface red-shift, gravitational redshift are investigated and the stability of the stellar configuration is discussed in details. Our model is free from central singularities and satisfies all energy conditions. The model we present here satisfy the static stability criterion, i.e. for g/cm3 (stable region) and for g/cm3, the region is unstable i.e. . [ABSTRACT FROM AUTHOR]

In the present paper, we discover a new well-behaved charged anisotropic solution of Einstein-Maxwell's field equations. We ansatz the metric potential of the form given by Maurya et al. ( Eur. Phys. J. C 76(12) (2016) 693) with . In their paper, it is mentioned that for , the solution is not well-behaved for neutral configuration as the speed of sound is nondecreasing radially outward. However, the solution can represent a physically possible configuration with the inclusion of some net electric charge, i.e. the solution can become a well-behaved solution with decreasing sound speed radially outward for a charged configuration. Due to the inclusion of electric charge, the solution leads to a very stiff equation-of-state (EoS) with the velocity of sound at the center and the compactness parameter is close to the Buchdahl limit 0.889. This stiff EoS support a compact star configuration of mass and radius of 10.1km. [ABSTRACT FROM AUTHOR]

In this paper, we present a model of a compact relativistic anisotropic star in the presence of an electric field. In order to obtain an exact solution of the Einstein-Maxwell field equations, we assume that the stellar material inside the star obeys a Chaplygin equation of state which is a nonlinear relationship between the radial pressure and the matter density. Using Tolman's metric potential for , we obtain the other metric co-efficient by employing the Karmarkar condition which is a necessary and sufficient condition for the interior spacetime of our model to be of embedding class I. Our stellar model is free from central singularity and obeys all the conditions for a realistic stellar object. [ABSTRACT FROM AUTHOR]

In this paper, we are willing to develop a model of an anisotropic star by choosing a new metric potential. All the physical parameters like the matter density, radial and transverse pressure are regular inside the anisotropic star, with the speed of sound less than the speed of light. So the new solution obtained by us gives satisfactory description of realistic astrophysical compact stars. The model of this paper is compatible with observational data of compact objects like RX J1856-37, Her X-1, Vela X-12 and Cen X-3. A particular model of Her X-1 (Mass 0.98 and radius=6.7 km.) is studied in detail and found that it satisfies all the condition needed for physically acceptable model. Our model is described analytically as well as with the help of graphical representation. [ABSTRACT FROM AUTHOR]

In this paper, we construct thin-shell wormholes in (2 + 1)-dimensions from noncommutative BTZ black hole by applying the cut-and-paste procedure implemented by Visser. We calculate the surface stresses localized at the wormhole throat by using the Darmois-Israel formalism and we find that the wormholes are supported by matter violating the energy conditions. In order to explore the dynamical analysis of the wormhole throat, we consider that the matter at the shell is supported by dark energy equation of state (EoS) p = ωρ with ω < 0. The stability analysis is carried out of these wormholes to linearized spherically symmetric perturbations around static solutions. Preserving the symmetry we also consider the linearized radial perturbation around static solution to investigate the stability of wormholes which was explored by the parameter β (speed of sound). [ABSTRACT FROM AUTHOR]