In the framework of Teleparallel Gravity, we derive a charged non-vacuum solution for a
physically symmetric tetrad field with two unknown functions of radial coordinate. The field …

We discuss possible variations of the effective gravitational constant with length scale,
predicted by most of alternative theories of gravity and unified models of physical …

We consider wormhole geometries subject to a gravitational action consisting of nonlinear
powers of the Ricci scalar. Specifically, wormhole throats are studied in the case where …

In this work, we consider time-dependent dark-energy star models, with an evolving
parameter ω crossing the phantom divide ω=-1. Once in the phantom regime, the null …

This manuscript is related to the construction of relativistic core-envelope model for
spherically symmetric charged anisotropic compact objects. The polytropic equation of state …

We derive a general set of acceptable junction conditions for F (T) gravity via the variational
principle. The analysis is valid for both the traditional form of F (T) gravity theory as well as …

The General Theory of Relativity: A Mathematical Exposition will serve readers as a modern
mathematical introduction to the general theory of relativity. Throughout the book, examples …

General hypersurface layers are considered in order to describe braneworlds and shell
cosmologies. No restriction is placed on the causal character of the hypersurface which may …

We classify the existent Birkhoff-type theorems into four classes: first, in field theory, the
theorem states the absence of helicity 0-and spin 0-parts of the gravitational field. Second, in …

Gravitation as a fundamental interaction that governs all phenomena at large and very small
scales, but still not well understood at a quantum level, is a cardinal missing link in …