Results 81 to 90 of about 695,554 (157)
Perturbations in loop quantum cosmology [PDF]
arXiv, 2012 The era of precision cosmology has allowed us to accurately determine many important cosmological parameters, in particular via the CMB. Confronting Loop Quantum Cosmology with these observations provides us with a powerful test of the theory. For this to be possible we need a detailed understanding of the generation and evolution of inhomogeneous ...
arxiv
Wstęp do bayesowskiej metodologii współczesnej kosmologii
Zagadnienia Filozoficzne w Nauce, 2009 The Bayesian framework is used in reconstruction of modern cosmology which actually concentrates on estimation of model parameters. The authors demonstrate that observational cosmology should be treated as an effective theory of the Universe. It realizes
Aleksandra Kurek +3 more
doaj
How accurately can we measure the hydrogen 2S->1S transition rate from the cosmological data?
, 2012 Recent progress in observational cosmology, and especially the forthcoming PLANCK mission data, open new directions in so-called precision cosmology. In this paper we illustrate this statement considering the accuracy of cosmological determination of the
Burigana, Carlo +4 more
core +1 more source
The Matter Bounce Alternative to Inflationary Cosmology [PDF]
arXiv, 2012 A bouncing cosmology with an initial matter-dominated phase of contraction during which scales which are currently probed with cosmological observations exit the Hubble radius provides a mechanism alternative to inflation for producing a nearly scale-invariant spectrum of cosmological perturbations.
arxiv
Age of Massive Galaxies at Redshift 8
The Astrophysical JournalRecent James Webb Space Telescope data analyses have shown that massive red galaxies existed at redshifts z ≳ 6, a discovery that is difficult to understand in the context of standard cosmology (ΛCDM).
M. López-Corredoira +3 more
doaj +1 more source
, 2019 Despite the observational success of the standard model of cosmology, present-day observations do not tightly constrain the nature of dark matter and dark energy and modifications to the theory of general relativity.
Marra, Valerio +2 more
core +1 more source
Why the measured cosmological constant is small [PDF]
arXiv, 2015 In a quest to explain the small value of the today's cosmological constant, following the approach introduced in [1], we show that the theoretical value of cosmological constant is consistent with its observational value. In more detail, we study the Freidmann-Lama\^{\i}tre-Robertson-Walker cosmology embedded isometrically in an $11$-dimensional ...
arxiv
Observational constraints on power-law cosmologies [PDF]
, 1999 Manoj Kaplinghat +3 more
openalex +1 more source
Late Decaying Dark Matter, Bulk Viscosity and the Cosmic Acceleration
, 2008 We discuss a cosmology in which cold dark matter begins to decay into relativistic particles at a recent epoch (z < 1). We show that the large entropy production and associated bulk viscosity from such decays leads to an accelerating cosmology as ...
A. G. Doroshkevich +11 more
core +1 more source