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This paper studies the complex mechanism of evolving charged self-gravitational (dissipating or non-dissipating) systems using a structure scalar Y T F , resulting from the basic procedure of orthogonal decomposition of the Riemann–Christoffel curvature tensor. The influence of electrical charge on the complexity of the considered system is analyzed in detail. We find several analytical Einstein–Maxwell models fulfilling the quasi-homologous ( Q H ) evolution plus the vanishing complexity factor ( C F ′ ) condition. Few of the presented models fulfill the Darmois constraints and exhibit shells, however, others satisfy the Israel constraints on both the boundary surfaces. Finally, some possible applications of the presented solutions are mentioned, which are important from astrophysical stand points. It is expected that some of the provided evolving Einstein–Maxwell fluid configurations may be utilized as a toy model of general frameworks like supernova explosions. It is found that the Q H implies the vanishing of the C F and gives rise to a unique and simplest configuration (Friedmann–Lemaître–Robertson–Walker model) fulfilling the condition Y T F = 0 and evolving in the Q H regime. [ABSTRACT FROM AUTHOR]

In this paper, we analyze a few physical characteristics of gravastar with cylindrical geometry in f (R , T) theory, where R is the Ricci scalar and T is the trace of energy-momentum tensor. The gravastar is generally considered to be a substitute of a black hole with three different regions. In this work, we examine the formulation of gravastar-like cylindrical structures in f (R , T) theory. By using Darmois and Israel matching conditions, we formulate a mass function of a thin shell. We calculate the different physical characteristics of gravastar, in particular, entropy within the thin shell, proper length of the intermediate thin shell as well as energy of the shell. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the effects of shear viscosity on a dissipative spherical collapse in the presence of heat dissipation and anisotropic pressure. In the background of f (R , T , Q) gravity, where R is Ricci scalar, T constitutes the trace of energy–momentum tensor, and Q ≡ R μ ν T μ ν , we examine the particular role of shear viscosity on the dynamical equations, and couple it with the heat transport equation, which is interpreted by Israel–Stewart theory. We reacquire the reduction in the inertial mass density of the matter with the addition of viscosity terms, by a factor (1 − α) which depends upon the inner states of thermodynamics. With the conformity of the equivalence relationship, the decline in inertial density is very close to gravitational force. To determine the particular results, we construct a relationship of Weyl tensor with distinctive matter variables. We study the inhomogeneous characteristics of energy density in this scenario and examine the significant effects of modified gravity along with shear viscosity. [ABSTRACT FROM AUTHOR]

This paper is aimed to set up a thin-shell gravastar model and address its physically accepted features in the background of noncommutative geometry. For this purpose, we have considered the cylindrically symmetric interior metric matched with suitable noncommutative exterior geometry using Israel boundary conditions. The stability of this thin-shell as well as thermodynamical stability is then explored under linear perturbations around the throat. We have found the stable regions near the horizon with some specific values of the involved parameters. [ABSTRACT FROM AUTHOR]