Results 1 to 10 of about 310,039 (247)
Intrinsic Entropy of Squeezed Quantum Fields and Nonequilibrium Quantum Dynamics of Cosmological Perturbations [PDF]
Entropy, 2021 Density contrasts in the universe are governed by scalar cosmological perturbations which, when expressed in terms of gauge-invariant variables, contain a classical component from scalar metric perturbations and a quantum component from inflaton field ...
Jen-Tsung Hsiang, Bei-Lok Hu
doaj +4 more sources
Unravelling cosmological perturbations
Physics Letters B, 2018 We explain in detail the quantum-to-classical transition for the cosmological perturbations using only the standard rules of quantum mechanics: the Schrödinger equation and Born's rule applied to a subsystem. We show that the conditioned, i.e. intrinsic,
Timothy J. Hollowood
doaj +5 more sources
Physics Letters B, 2022 Parity violating models based on the symmetric teleparallel gravity have been considered in the literature, but their applications in cosmology and especially the features in cosmological perturbations have not been fully explored.
Mingzhe Li, Dehao Zhao
doaj +3 more sources
Braneworld cosmological perturbations in teleparallel gravity
Physics Letters B, 2015 In this paper we find the fully gauge invariant cosmological perturbation equations in braneworld teleparallel gravity. In this theory, perturbations are the result of small fluctuations in the pentad field. We derive the gauge invariant 'potentials' for
A. Behboodi, K. Nozari
doaj +3 more sources
Quantum State Evolution in an Environment of Cosmological Perturbations
Universe, 2021 We study the pure and thermal states of quantized scalar and tensor perturbations in various epochs of Universe evolution. We calculate the density matrix of non-relativistic particles in an environment of these perturbations.
Zbigniew Haba
doaj +2 more sources
Zero average values of cosmological perturbations as an indispensable condition for the theory and simulations [PDF]
European Physical Journal C, 2015 Branislav Vlahovic, Maxim Eingorn
exaly +2 more sources
Linear cosmological perturbations in scalar-tensor-vector gravity
Physics Letters B, 2020 We investigate the cosmological perturbations in the context of a Scalar-Tensor-Vector theory of Gravity known as MOG in the literature. Recent investigations show that MOG reproduces a viable background cosmological evolution comparable to ΛCDM. However,
Sara Jamali +2 more
doaj +1 more source
No Intrinsic Decoherence of Inflationary Cosmological Perturbations
Universe, 2022 After a brief summary of the four main veins in the treatment of decoherence and quantum to classical transition in cosmology since the 1980s, we focus on one of these veins in the study of quantum decoherence of cosmological perturbations in ...
Jen-Tsung Hsiang, Bei-Lok Hu
doaj +1 more source
Cosmological Perturbations in Double Field Theory
Journal of High Energy Physics, 2023 We explore perturbative double field theory about time-dependent (cosmological) backgrounds to cubic order. To this order the theory is consistent in a weakly constrained sense, so that for a toroidal geometry it encodes both momentum and genuine winding
Olaf Hohm, Allison F. Pinto
doaj +1 more source
The MESS of cosmological perturbations
Physics Letters B, 2018 We introduce two new effective quantities for the study of comoving curvature perturbations ζ: the space dependent effective sound speed (SESS) and the momentum dependent effective sound speed (MESS).
Antonio Enea Romano +1 more
doaj +1 more source