Bounce inflation in cosmology: A unified inflaton-quintessence field

K Bamba, GGL Nashed, W El Hanafy, SK Ibraheem - Physical Review D, 2016 - APS
We investigate a bounce inflation model with a graceful exit into the Friedmann-Robertson-
Walker (FRW) decelerated Universe within f (T)-gravity framework, where T is the torsion …

H0 tension and the phantom regime: a case study in terms of an infrared f (T) gravity

A El-Zant, W El Hanafy, S Elgammal - The Astrophysical Journal, 2019 - iopscience.iop.org
We propose an f (T) teleparallel gravity theory including a torsional infrared (IR) correction.
We show that the governing Friedmann's equations of a spatially flat universe include a …

The hidden flat like universe II: Quasi inverse power law inflation by gravity

W El Hanafy, GGL Nashed - Astrophysics and Space Science, 2016 - Springer
In a recent work, a particular class of f (T) f(T) gravity, where TT is the teleparallel torsion
scalar, has been derived. This class has been identified by flat-like universe (FLU) …

On the relation between mass and charge: a pure geometric approach

MI Wanas - International Journal of Geometric Methods in Modern …, 2007 - World Scientific
A new solution to the field equations of the generalized field theory, constructed by Mikhail
and Wanas in 1977, has been obtained. The geometric structure used, in the present …

Origin of 1015–1016 G magnetic fields in the central engine of gamma ray bursts

RS de Souza, R Opher - Journal of Cosmology and Astroparticle …, 2010 - iopscience.iop.org
Various authors have suggested that the gamma-ray burst (GRB) central engine is a rapidly
rotating, strongly magnetized,(∼ 10 15–10 16 G) compact object. The strong magnetic field …

Generic phase portrait analysis of finite-time singularities and generalized Teleparallel gravity

W El Hanafy, GGL Nashed - Chinese Physics C, 2017 - iopscience.iop.org
We analyze the four common types of finite-time singularity using a generic framework of the
phase portrait geometric approach. This technique requires the Friedmann system to be …

Initial singularity and pure geometric field theories

MI Wanas, MM Kamal, TF Dabash - The European Physical Journal Plus, 2018 - Springer
In the present article we use a modified version of the geodesic equation, together with a
modified version of the Raychaudhuri equation, to study initial singularities. These modified …

Unification principle and a geometric field theory

MI Wanas, SN Osman, RI El-Kholy - Open Physics, 2015 - degruyter.com
In the context of the geometrization philosophy, a covariant field theory is constructed. The
theory satisfies the unification principle. The field equations of the theory are constructed …

Spacetime structure and electromagnetism

MI Wanas, SA Ammar - Modern Physics Letters A, 2010 - World Scientific
Two Lagrangian functions are used to construct geometric field theories. One of these
Lagrangians depends on the curvature of space, while the other depends on curvature and …

Unification Principle and a Cosmological Model

MI Wanas, S Nabil Osman, NE Abdelhamid - Gravitation and Cosmology, 2019 - Springer
We present a cosmological model constructed using a pure geometric field theory. The
unification principle implies defining any physical object in the model using the building …