Do you want to publish a course? Click here

Anisotropic relativistic fluid spheres in the Buchdahl model

52   0   0.0 ( 0 )
 Added by Jitendra Kumar Dr.
 Publication date 2021
  fields Physics
and research's language is English




Ask ChatGPT about the research

In this work, we present a class of relativistic and well-behaved solution to Einsteins field equations describing anisotropic matter distribution. We perform our analysis by proposing a Buchdahl ansatz which represents almost all the known analytic solutions to the spherically symmetric, static Einstein equations with a perfect fluid source, including, in particular, the Vaidya-Tikekar. We have considered three different cases for generalized Buchdahl dimensionless parameter K. Our suggested solution is free from physical and geometric singularities, satisfies causality condition, and relativistic adiabatic index(gamma), and exhibits well-behaved nature, as well as, all energy conditions and equilibrium condition are well-defined, which implies that our model is physically acceptable.



rate research

Read More

In the present study we have proposed a new model of an anisotropic compact star which admits the Chaplygin equation of state. For this purpose, we consider Buchdahl ansatz. We obtain the solution of proposed model in closed form which is non-singular, regular and well-behaved. In addition to this, we show that the model satisfies all the energy conditions and maintains the hydrostatic equilibrium equation. This model represents compact stars like PSR B0943+10, Her X-1 and SAX J1808.4-3658 to a very good approximate.
In this paper, we study the stellar structure in terms of alternative theory of gravity specially by f (R;T) gravity theory. Here, we consider the function f (R;T) = R+2VT where R is the Ricci scalar, T is the stress-energy momentum and V is the coupling constant. Using it we developed a stellar model that briefly explains the isotropic matter distribution within the compact object filled with perfect fluid. The stability of the model is shown by several physical and stability conditions. With the accecptibility of our theory, we were able to collect data for compact stars like PSR-B0943+10, CEN X-3, SMC X-4, Her X-1 and 4U1538-52 with great accuracy.
We study a spherically symmetric spacetime made of anisotropic fluid of which radial equation of state is given by $p_1 = -rho$. This provides analytic solutions and a good opportunity to study the static configuration of black hole plus matter. For a given equation-of-state parameter $w_2 = p_2/rho$ for angular directions, we find exact solutions of the Einsteins equation described by two parameters. We classify the solution into six types based on the behavior of the metric function. Depending on the parameters, the solution can have event and cosmological horizons. Out of these, one type corresponds to a generalization of the Reissiner-Nordstrom black hole, for which the thermodynamic properties are obtained in simple forms. The solutions are stable under radial perturbations.
223 - Hyeong-Chan Kim 2017
We study spherically symmetric geometries made of anisotropic perfect fluid based on general relativity. The purpose of the work is to find and classify black hole solutions in closed spacetime. In a general setting, we find that a static and closed space exists only when the radial pressure is negative but its size is smaller than the density. The Einstein equation is eventually casted into a first order autonomous equation on two-dimensional plane of scale-invariant variables, which are equivalent to the Tolman-Oppenheimer-Volkoff (TOV) equation in general relativity. Then, we display various solution curves numerically. An exact solution describing a black hole solution in a closed spacetime was known in Ref. [1], which solution bears a naked singularity and negative energy era. We find that the two deficits can be remedied when $rho+3p_1>0$ and $rho+p_1+2p_2< 0$, where the second violates the strong energy condition.
Interested in the collapse of a radiating star, we study the temporal evolution of a fluid with heat flux and bulk viscosity, including anisotropic pressure. As a starting point, we adopt an initial configuration that satisfies the regularities conditions as well as the energy conditions to a certain range of the mass-radius ratio for the star, defining acceptable models. For this set of models, we verify that the energy conditions remain satisfied until the black hole formation. Astrophysical relevant quantities, such as the luminosity perceived by an observer at infinity, the time of event horizon formation and the loss of mass during the collapse are presented.
comments
Fetching comments Fetching comments
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا