Orthogonal Splitting Of Riemann Tensor Research Articles

Cluster of stars in f(, T) gravity

This paper is devoted to analyze the dynamical impacts of gravity model on the cluster of stars. For this motive, we consider the spherically symmetric interior geometry with anisotropic fluid as analogous to cluster of stars distributions. We express the modified field equations by taking a particular model of , i.e. . In order to explore the evolutionary behavior of cluster of stars, the observational data of a compact star 4U1820 − 30 is used. We construct the modified scalar functions by orthogonal splitting of Riemann tensor in theory of gravity and find the factors causing density irregularities in the framework. We calculate the evolution parameters by using these scalar functions. Moreover, we also investigate the structure scalars for dust ball. The dynamical effects on cluster of stars are examined via structure scalars in the presence of Gauss-Bonnet gravity. It is found that Gauss-Bonnet parameter representing exotic material in the cluster plays a vital role in governing the dynamics of cluster of stars.

Measure of complexity in self-gravitating systems using structure scalars

The aim of this paper is to present the definition of complexity for static self-gravitating anisotropic matter proposed in f(G,T)theory, where Gis the Gauss-Bonnet term and Tis the trace of energy momentum tensor. We evaluate field equations, Tolman-Oppenheimer-Volkoff equation, mass functions and structure scalars. Among the calculated modified scalar variables that are obtained from the orthogonal splitting of Riemann tensor, a single scalar function has been identified as the complexity factor. After exploring the corresponding Tolmann mass function, it is seen that the complexity factor along with the f(G,T)terms have greatly influenced its formulation and its role in the subsequent radial phases of the spherical system. We have also used couple of ansatz in order to discuss possible solutions of equations of motion in the study of the structure of compact object.

Expansion-free self-gravitating dust dissipative fluids

The present study deals with the spherically symmetric distributions of dust dissipative fluids with a central vacuum cavity, evolving under the condition of vanishing of expansion scalar. The work is based on two aspects—on the one hand the description of model in terms of structures scalars emerging in the orthogonal splitting of Riemann tensor. Secondly, to obtain the solutions of dynamical equations under some special cases and assumption on implicit function of variables. The solutions here discussed, model the evolution of the vacuum cavity of fluid distribution, thereby showing the potential of expansion free motion.

Lemaitre-Tolman-Bondi dust spacetimes: Symmetry properties and some extensions to the dissipative case

We consider extensions of Lemaitre-Tolman-Bondi (LTB) spacetimes to the dissipative case. For doing that we previously carry out a systematic study on LTB. This study is based on two different aspects of LTB. On the one hand, a symmetry property of LTB will be presented. On the other hand, the description of LTB in terms of some fundamental scalar functions (structure scalars) appearing in the orthogonal splitting of Riemann tensor will be provided. We shall consider as "natural" generalizations of LTB (hereafter referred to as GLTB) either those metrics admitting some similar kind of symmetry as LTB, or those sharing structure scalars with similar dependence on the metric.