Results 21 to 30 of about 193,127 (291)
Constraining the $\Lambda$CDM and Galileon models with recent cosmological data [PDF]
, 2017 The Galileon theory belongs to the class of modified gravity models that can explain the late-time accelerated expansion of the Universe. In previous works, cosmological constraints on the Galileon model were derived, both in the uncoupled case and with ...
Astier, P. +6 more
core +4 more sources
Non-singular radiation cosmological models [PDF]
, 2004 In this paper we analyse the possibility of constructing singularity-free inhomogeneous cosmological models with a pure radiation field as matter content.
Baldwin O. R. +10 more
core +3 more sources
Influence of the cosmological expansion on small systems [PDF]
, 2001 The effect of the large-scale cosmological expansion on small systems is studied in the light of modern cosmological models of large-scale structure.
Dominguez, Alvaro, Gaite, Jose
core +2 more sources
A Generalized Solution of Bianchi Type-V Models with Time-Dependent G and Λ
Universe, 2018 We study the homogeneous but anisotropic Bianchi type-V cosmological model with time-dependent gravitational and cosmological “constants”. Exact solutions of the Einstein field equations (EFEs) are presented in terms of adjustable parameters ...
Alnadhief H. A. Alfedeel +2 more
doaj +1 more source
Inhomogeneous cosmological models: exact solutions and their applications [PDF]
, 2011 Recently, inhomogeneous generalisations of the Friedmann-Lemaitre-Robertson-Walker cosmological models have gained interest in the astrophysical community and are more often employed to study cosmological phenomena.
Bolejko, Krzysztof +2 more
core +2 more sources
, 2001 6 pages, gc.sty; to appear in special issue of Gravitation and Cosmology (G@C) devoted to Quantum Gravity, Unified Models and Strings to mark 100th anniversary of Tomsk State Pedagogical University, Ed. Prof. S.
Aceves de la Cruz, F. +3 more
openaire +3 more sources
Quantum cosmological perfect fluid models [PDF]
, 2001 Perfect fluid Friedmann-Robertson-Walker quantum cosmological models for an arbitrary barotropic equation of state $p = \alpha\rho$ are constructed using Schutz's variational formalism. In this approach the notion of time can be recovered.
A. G. Riess +22 more
core +4 more sources
A Bias-free Cosmological Analysis with Quasars Alleviating H 0 Tension
The Astrophysical Journal Supplement Series, 2023 Cosmological models and their parameters are widely debated because of theoretical and observational mismatches of the standard cosmological model, especially the current discrepancy between the value of the Hubble constant, H _0 , obtained by Type Ia ...
Aleksander Łukasz Lenart +4 more
doaj +1 more source
Non-singular pre-big bang scenarios from all-order α′ corrections
Journal of High Energy Physics, 2023 We reformulate in Hamiltonian language the recent proposal by Hohm and Zwiebach of an action yielding the most general O(d, d)-symmetric string cosmology equations, at tree-level in the string-loop expansion, but to all orders in the α′ expansion.
M. Gasperini, G. Veneziano
doaj +1 more source
Journal of High Energy Physics, 2023 Nonlinear sigma models on de Sitter background have proved a useful prototype for quantum gravity in summing the large logarithms which arise from loop corrections.
R. P. Woodard, B. Yesilyurt
doaj +1 more source