Results 11 to 20 of about 15,205 (269)
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.
openaire +5 more sources
Tachyon field in loop cosmology
Physics Letters B, 2020 The evolutionary pictures of tachyon field in modified loop cosmology have been investigated. We present the dynamical behavior of the tachyon field associated with an exponential potential and find that the pre-inflation dynamics are very similar in ...
Kui Xiao
doaj +1 more source
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
openaire +4 more sources
International Journal of Modern Physics D, 1999 The notion of time in cosmology is revealed through an examination of transition matrix elements of radiative processes occurring in the cosmos. To begin with, the very concept of time is delineated in classical physics in terms of correlations between the succession of configurations which describe a process and a standard trajectory called the clock.
Brout, Hyman Robert, Parentani, Renaud
openaire +5 more sources
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
openaire +5 more sources
Bootstrapped Newtonian Cosmology and the Cosmological Constant Problem [PDF]
Symmetry, 2021 Bootstrapped Newtonian gravity was developed with the purpose of estimating the impact of quantum physics in the nonlinear regime of the gravitational interaction, akin to corpuscular models of black holes and inflation. In this work, we set the ground for extending the bootstrapped Newtonian picture to cosmological spaces.
Casadio, Roberto, Giusti, Andrea
openaire +2 more sources
International Journal of Modern Physics D, 2012 Using a new effective action predicted from quantum gravity where the sign of the Euclidean Einstein action is reversed, we discuss Wentzel–Kramers–Brillouin (WKB) solutions in quantum cosmology and predict that this sign change might explain the origin of phantom scalars.
Arundhati Dasgupta, Adamantia Zampeli
openaire +2 more sources
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
openaire +3 more sources
COSMOLOGY IN ISLAM, CONSTRUCTING ISLAMIZATION OF NATURE SCIENCE
Jurnal Al-Dustur, 2022 Cosmology is one of the philosophical and scientific objects that become attention in Greek philosophers, especially Aristotle. However, with the times, this cosmology was found in The Qur’an, exactly in the concept of the sky and earth creation which ...
Muhammad Fiqih Cholidi, Safiya Fadlulah
doaj +1 more source
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
openaire +2 more sources