Results 1 to 10 of about 903 (200)
Unravelling cosmological perturbations [PDF]
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 +4 more sources
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 +2 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 +1 more source
Scalar cosmological perturbations [PDF]
Classical and Quantum Gravity, 2012 Scalar perturbations of Friedmann-Lemaitre cosmologies can be analyzed in a variety of ways using Einstein's field equations, the Ricci and Bianchi identities, or the conservation equations for the stress-energy tensor, and possibly introducing a timelike reference congruence.
Uggla, Claes, Wainwright, John
openaire +2 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 +1 more source
Cosmological perturbations [PDF]
Physics Reports, 2009 We review the study of inhomogeneous perturbations about a homogeneous and isotropic background cosmology. We adopt a coordinate based approach, but give geometrical interpretations of metric perturbations in terms of the expansion, shear and curvature of constant-time hypersurfaces and the orthogonal timelike vector field.
Malik, KA, Wands, D
openaire +3 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 antigravity [PDF]
Physical Review D, 2014 15 pages, a few references ...
Oltean, Marius, Brandenberger, Robert
openaire +2 more sources
Relativistic Hydrodynamic Cosmological Perturbations [PDF]
General Relativity and Gravitation, 1999 16 pages, no figure, To appear in Gen.
Hwang, Jai-chang, Noh, Hyerim
openaire +3 more sources