This paper deals with the dynamics of cylindrical collapse anisotropic matter configuration in context energy-momentum squared gravity. covariant generalization general relativity allows presence T_abT^ab action functional theory. Consequently, relevant field equations are different from only sources. In this theory, there is a maximum energy density and minimum scale factor early universe. mea...

Model of gravitational collapse anisotropic compact stars in a new theory $ f(R) gravity has been developed. The author considers the modified model = \xi R^4 to investigate physically acceptable stars. First, presents brief review development field equations for particular interior metric Then analytical solutions various physical quantities collapsing have By analyzing plots parameters and co...

The existence of extremely dark and compact astronomical bodies is by now a well established observational fact. On the other hand, classical General Relativity predicts the existence of black holes which fit very well with the observations, but do lead to important conceptual problems. In this contribution we ask ourselves the straightforward question: Are the dark and compact objects that we ...

According to Penrose, the fundamental conflict between the superposition principle of quantum mechanics and the principle of general covariance of general relativity entails the existence of wavefunction collapse, e.g. a quantum superposition of two different space-time geometries will collapse to one of them due to the ill-definedness of the time-translation operator for the superposition. In ...

Modifications to the gravitational potential affect the nonlinear gravitational evolution of large scale structures in the Universe. To illustrate some generic features of such changes, we study the evolution of spherically symmetric perturbations when the modification is of Yukawa type; this is nontrivial, because we should not and do not assume that Birkhoff ’s theorem applies. We then show h...

In this paper, by making use of the perturbative expansion around topological field theory we are trying to understand why the standard perturbation theory for General Relativity, which starts with linearized gravity does not see gravitational collapse. We start with investigating classical equations of motion. For zero Immirzi parameter the ambiguity of the standard perturbative expansion is r...