Results 31 to 40 of about 32,545 (270)
Dark photon dark matter in the presence of inhomogeneous structure
Journal of High Energy Physics, 2020 Dark photon dark matter will resonantly convert into visible photons when the dark photon mass is equal to the plasma frequency of the ambient medium. In cosmological contexts, this transition leads to an extremely efficient, albeit short-lived, heating ...
Samuel J. Witte +3 more
doaj +1 more source
Inhomogeneities in the universe [PDF]
Classical and Quantum Gravity, 2011 30 pages, 10 figures. Accepted for publication in Classical and Quantum Gravity special issue "Inhomogeneous Cosmological Models and Averaging in Cosmology".
openaire +4 more sources
Inhomogeneous cosmologies, the Copernican principle and the cosmic microwave background: More on the EGS theorem [PDF]
, 2003 We discuss inhomogeneous cosmological models which satisfy the Copernican principle. We construct some inhomogeneous cosmological models starting from the ansatz that the all the observers in the models view an isotropic cosmic microwave background.
A. A. Coley +44 more
core +2 more sources
Inhomogeneous spacetimes in Weyl integrable geometry with matter source
European Physical Journal C: Particles and Fields, 2020 We investigate the existence of inhomogeneous exact solutions in Weyl Integrable theory with a matter source. In particular, we consider the existence of a dust fluid source while for the underlying geometry we assume a line element which belongs to the ...
Andronikos Paliathanasis +2 more
doaj +1 more source
Interaction of Anisotropic Dark Energy with Generalized Hybrid Expansion Law
Advances in High Energy Physics, 2022 Interaction of dark energy in the anisotropic locally rotationally symmetric (LRS) Bianchi type-I metric is investigated in the context of modified fR,T theory of gravity, where R is the Ricci scalar and T is the trace of stress energy momentum tensor ...
Md Khurshid Alam +2 more
doaj +1 more source
Conditions for inflation in an initially inhomogeneous universe [PDF]
, 1994 Using a long wavelength iteration scheme to solve Einstein's equations near the Big-Bang singularity of a universe driven by a massive scalar field, we find how big initial quasi-isotropic inhomogeneities can be before they can prevent inflation to set ...
Deruelle, Nathalie, Goldwirth, Dalia S.
core +2 more sources
A Possible Explanation of Dark Matter and Dark Energy Involving a Vector Torsion Field
Universe, 2022 A simple gravitational model with torsion is studied, and it is suggested that it could explain the dark matter and dark energy in the universe. It can be reinterpreted as a model using the Einstein gravitational equations where spacetime has regions ...
Graeme W. Milton
doaj +1 more source
Cosmological acceleration from structure formation [PDF]
, 2006 We discuss the Buchert equations, which describe the average expansion of an inhomogeneous dust universe. In the limit of small perturbations, they reduce to the Friedmann-Robertson-Walker equations.
Padmanabhan T. +3 more
core +3 more sources
Accelerated Lyra's Cosmology Driven by Electromagnetic Field in Inhomogeneous Universe
International Journal of Mathematics and Mathematical Sciences, 2009 A new class of cylindrically symmetric inhomogeneous cosmological models for perfect fluid distribution with electromagnetic field is obtained in the context of Lyra's geometry.
Anirudh Pradhan, Padmini Yadav
doaj +1 more source
Spin Hall effect of light in inhomogeneous axion field
Physics Letters B, 2020 We study the spin transport of light in weakly inhomogeneous axion field in a flat Robertson-Walker universe and derive the spin Hall effect for circularly polarized rays.
Mansoureh Hoseini, Mohammad Mehrafarin
doaj +1 more source