Results 1 to 10 of about 299,841 (224)
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
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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
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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Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 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
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Braneworld cosmological perturbations in teleparallel gravity
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 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
Avisa Behboodi, Kourosh Nozari
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Cosmological Perturbations in Bouncing Cosmologies and the Case of the Pre-Big Bang Scenario
Universe, 2022 Pre-Big Bang cosmology inspired generations of cosmologists in attempts to cure the initial Big Bang singularity using a fundamental length scale as proposed by string theory.
Valerio Bozza
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Cosmological Perturbations in Phantom Dark Energy Models
Universe, 2017 The ΛCDM paradigm, characterised by a constant equation of state w = − 1 for dark energy, is the model that better fits observations. However, the same observations strongly support the possibility of a dark energy content where the corresponding
João Morais +2 more
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Effective speed of cosmological perturbations
Physics of the Dark UniverseThe first version of this paper was submitted to JCAP on February 7th 2023, and the first report was received on January 14th 2024.
Antonio Enea Romano
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On the symmetries of cosmological perturbations [PDF]
Journal of Cosmology and Astroparticle Physics, 2020 The space of inflationary models is vast, containing wide varieties of mechanisms, symmetries, and spectra of particles. Consequently, the space of observational signatures is similarly complex. Hence, it is natural to look for boundaries of the space of models and their signatures.
Green, Daniel, Pajer, Enrico
openaire +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