Results 51 to 60 of about 6,154 (134)
Ultraviolet-regularized power spectrum without infrared distortions in cosmological spacetimes
Physics Letters B, 2023 We reexamine the regularization of the two-point function of a scalar field in a Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime. Adiabatic regularization provides a set of subtraction terms in momentum space that successfully remove its ultraviolet
Antonio Ferreiro, Francisco Torrenti
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European Physical Journal C: Particles and Fields, 2018 We numerically integrate the Einstein’s equations for a spatially flat Friedmann–Lemaire–Robertson–Walker (FLRW) background spacetime with a spatial curvature perturbation and evolving primordial tensor perturbations using the Einstein Toolkit.
Ke Wang
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Dynamic wormhole geometries in hybrid metric-Palatini gravity
European Physical Journal C: Particles and Fields, 2021 In this work, we analyse the evolution of time-dependent traversable wormhole geometries in a Friedmann–Lemaître–Robertson–Walker background in the context of the scalar–tensor representation of hybrid metric-Palatini gravity.
Mahdi Kord Zangeneh +1 more
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Boson mixing and flavor vacuum in the expanding Universe: A possible candidate for the dark energy
Physics Letters B, 2023 We analyze the boson mixing in curved spacetime and compute the expectation value of the energy-momentum tensor of bosons on the flavor vacuum in spatially flat Friedmann-Lemaître-Robertson-Walker metrics.
Antonio Capolupo, Aniello Quaranta
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Quantization of Friedmann-Robertson-Walker spacetimes in the presence of a negative cosmological constant and radiation [PDF]
Physical Review D, 2006 34 pages, 3 ...
Monerat, G. A. +4 more
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MathematicsApplications of Parametrized Relativistic Quantum Theory (PRQT) in curved spacetime are considered here. PRQT in curved spacetime is applied to the motion of free scalar particles in expanding universe metrics, including a generalized expanding universe (
John R. Fanchi
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Comment on “Quantization of Friedmann-Robertson-Walker spacetimes in the presence of a negative cosmological constant and radiation” [PDF]
Physical Review D, 2007 The quantization of the Friedmann-Robertson-Walker spacetime in the presence of a negative cosmological constant was used in a recent paper to conclude that there are solutions that avoid singularities (big bang-big crunch) at the quantum level.
Paolo Amore +4 more
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Particle decay in expanding Friedmann-Robertson-Walker universes [PDF]
Physical Review D, 2018 The lack of energy conservation introduces new particle processes in curved spacetime that are forbidden in flat space. Therefore one has to be very cautious about using the results calculated in Minkowskian space in early universe applications.
Juho Lankinen, I. Vilja
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Physics Letters B, 2021 We demonstrate that the rapidity and robustness of slow contraction in homogenizing and flattening the universe found in simulations in which the initial conditions were restricted to non-perturbative variations described by a single Fourier mode along ...
Anna Ijjas +3 more
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Scalar field dynamics in Friedmann-Robertson-Walker spacetimes [PDF]
Physical Review D, 1997 We study the non-linear dynamics of quantum fields in matter and radiation dominated universes, using the non-equilibrium field theory approach combined with the non-perturbative Hartree and the large N approximations. We examine the phenomenon of explosive particle production due to spinodal instabilities and parametric amplification in expanding ...
Boyanovsky, D. +5 more
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