Results 51 to 60 of about 17,519 (197)

Horizon, homogeneity and flatness problems: do their resolutions really depend upon inflation?

European Physical Journal C: Particles and Fields
The horizon problem, encountered in cosmology, is derived as such for world models based on Robertson–Walker metric where homogeneity and isotropy of the universe is assumed to begin with and is guaranteed for all epochs.
Ashok K. Singal
doaj   +1 more source

Global Dynamics of the Hořava–Lifshitz Cosmological Model in a Non-Flat Universe with Non-Zero Cosmological Constant [PDF]

, 2021
Fabao Gao, Jaume Llibre
openalex   +1 more source

Homogeneity, Flatness and "Large" Extra Dimensions [PDF]

, 2001
We consider a model in which the universe is the direct product of a (3+1)-dimensional Friedmann, Robertson-Walker (FRW) space and a compact hyperbolic manifold (CHM). Standard Model fields are confined to a point in the CHM (i.e. to a brane).
A. D. Linde, A. N. Kolmogorov, C. N. Lockhart, D. J. H. Chung, Dejan Stojkovic, G. D. Starkman, G. F. Ellis, Glenn D. Starkman, H. V. Fagundes, I. Antoniadis, I. Antoniadis, I. Antoniadis, J. A. Peacock, J. D. Lykken, J. R. Gott, K. Dienes, K. Dienes, L. Randall, L. Randall, Mark Trodden, N. Arkani-Hamed, N. Arkani-Hamed, N. J. Cornish, N. Kaloper, O. Heckmann, Ya. G. Sinai   +25 more
core   +2 more sources

UNIVERSE EVOLUTION IN A 5D RICCI-FLAT COSMOLOGY [PDF]

Modern Physics Letters A, 2006
We use Wetterich's parametrization equation of state (EOS) of dark energy to a 5D Ricci-flat cosmological solution and we assume that the universe contains three major components: matter, radiation and dark energy. By using the relation between the scale factor and the redshift z, we show that the two arbitrary functions contained in the 5D solution ...
Zhang, Chengwu, Liu, Hongya, Xu, Lixin, Wesson, P. S.   +3 more
openaire   +2 more sources

Asymptotic freedom, asymptotic flatness and cosmology [PDF]

Journal of Cosmology and Astroparticle Physics, 2013
Holographic RG flows in some cases are known to be related to cosmological solutions. In this paper another example of such correspondence is provided. Holographic RG flows giving rise to asymptotically-free $ $-functions have been analyzed in connection with holographic models of QCD.
openaire   +4 more sources

Cosmology and Conformally Flat Space. II

Hiroshima Mathematical Journal, 1941
Not ...
openaire   +3 more sources

Cosmology in Conformally Flat Spacetime

The Astrophysical Journal, 1997
A possible solution to cosmological age and redshift-distance difficulties has recently been proposed by applying the appropriate conformally flat spacetime (CFS) coordinates to the standard solution of the field equations in a standard dust model closed universe.
openaire   +1 more source

The cluster abundance in flat and open cosmologies [PDF]

Monthly Notices of the Royal Astronomical Society, 1996
Uuencoded package containing LaTeX file (uses mn.sty) plus 7 postscript figures incorporated using epsf. Total length 10 pages. Final version, to appear MNRAS. COBE comparison changed to 4yr data.
Viana, Pedro T P, Liddle, Andrew R
openaire   +3 more sources

A New Rarity Assessment of the “Disk of Satellites”: The Milky Way System Is the Exception Rather Than the Rule in the ΛCDM Cosmology

The Astrophysical Journal
The majority of satellite galaxies around the Milky Way (MW) show disk-like distributions (the disk of satellites; DoS), which is a small-scale problem of the lambda cold dark matter cosmology.
Chanoul Seo, Suk-Jin Yoon, Sanjaya Paudel, Sung-Ho An, Jun-Sung Moon   +4 more
doaj   +1 more source

Conformally Flat Bulk Tilted Cosmological Model

Journal of Physics: Conference Series, 2013
Conformally flat plane symmetric bulk viscous fluid tilted cosmological model is investigated. We assume that ζθ = K (constant), where ζ is the coefficient of bulk viscosity and θ is the expansion in the model. It has been assumed that the supplementary condition between metric potential as A = B n, where n is constant.
Anita Bagora, Rakeshwar Purohit
openaire   +1 more source