Results 11 to 20 of about 58,534 (245)
Cosmological Perturbations [PDF]
, 2002 The aim of these lecture notes is to familiarize graduate students and beginning postgraduates with the basic ideas of linear cosmological perturbation theory and of structure formation scenarios.
Tsagas, Christos G.
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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
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Non-minimal coupling influence on the deviation from de Sitter cosmological expansion
European Physical Journal C: Particles and Fields, 2018 We investigate the models of cosmological inflation in generalized scalar–tensor gravity, which we consider as a source of deviation from de Sitter dynamics in the case of GR.
I. V. Fomin, S. V. Chervon
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Matching conditions for cosmological perturbations [PDF]
Physical Review D, 1995 We derive the matching conditions for cosmological perturbations in a Friedmann Universe where the equation of state undergoes a sharp jump, for instance as a result of a phase transition. The physics of the transition which is needed to follow the fate of the perturbations is clarified.
Deruelle, Nathalie, Mukhanov, V. F.
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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
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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
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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
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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
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Cosmological perturbations in antigravity [PDF]
Physical Review D, 2014 15 pages, a few references ...
Oltean, Marius, Brandenberger, Robert
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Cosmological perturbations from stochastic gravity [PDF]
, 2008 In inflationary cosmological models driven by an inflaton field the origin of the primordial inhomogeneities which are responsible for large scale structure formation are the quantum fluctuations of the inflaton field.
A. A. Starobinsky +18 more
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