We investigate the Weyl space-time extension of general relativity. We have derived the equations of evolution for expansion, shear and rotation. We have performed the study of the FLRW cosmology through focusing and defocusing of the geodesic congruences in the Weyl space-time. In particular, ...
Astrophysics - Cosmology and Nongalactic AstrophysicsIn this paper we contrasted two cosmological perturbation theory formalisms, the1+3 covariant gauge invariantand thegauge invariant, by comparing the gauge invariant variables associated with the magnetic field defined in each approach. In the first ...
Recently, solutions of matrix models have been found [5,6,7], which can be interpreted as 3 + 1-dimensional quantum geometriesFootnote 1 describing an effective FLRW cosmology with a big bounce (BB). The underlying model is known as IKKT model [33], which has been proposed as a construc...
Horizon thermodynamics and cosmological equations in standard cosmology provide a holographic-like connection between thermodynamic quantities on a cosmological horizon and in the bulk. It is expected that this connection can be modified as a holographic-like thermodynamic relation for dissipative and non-...
Journal of Cosmology and Astroparticle PhysicsJ. Grande, J. Sola, S. Basilakos, and M. Plionis, Hubble expansion and structure formation in the 'running FLRW model' of the cosmic evolution, arXiv:1103.4632.J. Grande, J. Sola`, S. Basilakos and M. Plionis, Hubble expansion and ...
展开 关键词: Theoretical or Mathematical/ cosmology/ Friedman-Lemaitre-Robertson-Walker cosmological models large-scale homogeneity matter distribution energy distribution spatial curvature closed FLRW universes/ A9880D Theoretical cosmology A0420J Solutions to equations in general relativity DOI...
LRD Djordjevic - 《Classical & Quantum Gravity An Interantional Journal of Gravity Geometry of Field Theories Supergravity Cosmology》 被引量: 0发表: 2018年 Minisuperspace FLRW oscillator cosmological model and generalized uncertainty principle This paper deals with the effects of the generalized uncertai...
xing some initial data as he would do in standard 4D cosmology, will not be able to distinguish the time evolution of these data in the DGP model with large enough rc H , from what he would have observed in standard cosmology with the same initial data. 21 disregarding some possible ...
Tram, ThomasLesgourgues, JulienarXivJournal of Cosmology & Astroparticle PhysicsT. Tram and J. Lesgourgues, Optimal polarisation equations in FLRW universes, arXiv:1305.3261.T. Tram and J. Lesgourgues, Optimal polarisation equations in flrw universes, Journal of Cosmology and Astroparticle Physics ...
General Relativity and Quantum CosmologyIn the present paper we consider $f(R)$ gravity theories in the metric approach and we derive the equations of motion, focusing also on the boundary conditions. In such a way we apply the general equations to a first order perturbation expansion of the ...