Results 11 to 20 of about 385,645 (329)
Second international workshop on particle physics and the early universe (COSMO-98), 1999 The discussion of cosmological parameters used to be a source of embarrassment to cosmologists. Today, measurements of the cosmological parameters are leading the way into the era of precision cosmology.
Turner, Michael S.
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Cosmological Reionization [PDF]
Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, 2000 In popular cosmological scenarios, some time beyond a redshift of 10, stars within protogalaxies created the first heavy elements; these systems, together perhaps with an early population of quasars, generated the ultraviolet radiation and mechanical ...
C. S. Frenk +4 more
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Geometrothermodynamic Cosmology
Entropy, 2023 We review the main aspects of geometrothermodynamics, a formalism that uses contact geometry and Riemannian geometry to describe the properties of thermodynamic systems. We show how to handle in a geometric way the invariance of classical thermodynamics with respect to Legendre transformations, which means that the properties of the systems do not ...
Orlando Luongo, Hernando Quevedo
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Physical Review Letters, 2007 We explore nonlocally modified models of gravity, inspired by quantum loop corrections, as a mechanism for explaining current cosmic acceleration. These theories enjoy two major advantages: they allow a delayed response to cosmic events, here the transition from radiation to matter dominance, and they avoid the usual level of fine tuning; instead ...
Deser, S., Woodard, R. P.
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Physical Review D, 2020 We compute the quantum circuit complexity of the evolution of scalar curvature perturbations on expanding backgrounds, using the language of squeezed vacuum states. In particular, we construct a simple cosmological model consisting of an early-time period of de Sitter expansion followed by a radiation-dominated era and track the evolution of complexity
Arpan Bhattacharyya +3 more
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Scientific Reports, 2012 Prediction and control of the dynamics of complex networks is a central problem in network science. Structural and dynamical similarities of different real networks suggest that some universal laws might accurately describe the dynamics of these networks, albeit the nature and common origin of such laws remain elusive.
Krioukov, Dmitri +5 more
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COSMOLOGICAL ZITTERBEWEGUNG [PDF]
International Journal of Modern Physics D, 2013 We describe a new phenomenon of zitterbewegung of a free Dirac particle in cosmological spacetimes. Unlike the similar effect theorized by Schrödinger in 1930, the cosmological zitterbewegung is a real, physically attainable effect, which originates from the mixing of positive and negative frequency modes of a field operator in cosmological spacetimes.
Girdhar, Parth, Kobakhidze, Archil
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International Journal of Modern Physics: Conference Series, 2012 We review the difficulties of the generalized Chaplygin gas model to fit observational data, due to the tension between background and perturbative tests. We argue that such issues may be circumvented by means of a self-interacting scalar field representation of the model.
Julio C. Fabris +4 more
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Homogeneous cosmologies with a cosmological constant [PDF]
Physical Review D, 1999 Spatially homogeneous cosmological models with a positive cosmological constant are investigated, using dynamical systems methods. We focus on the future evolution of these models. In particular, we address the question whether there are models within this class that are de Sitter-like in the future, but are tilted.
Goliath, Martin, Ellis, George F. R.
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