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We show that the spatial structure of electromagnetic vacuum fluctuations, predicted by quantum electrodynamics, can be indirectly observed using thermal noise at radio frequencies. Using simple lab equipment like coaxial cables and RF…

Quantum Physics · Physics 2025-05-06 Sun-Hyun Youn

We focus on the dynamics of a Brownian particle whose mass fluctuates. First we show that the behaviour is similar to that of a Brownian particle moving in a fluctuating medium, as studied by Beck [Phys. Rev. Lett. 87 (2001) 180601]. By…

Statistical Mechanics · Physics 2007-06-13 R. Lambiotte , M. Ausloos

We develop a simple model to study classical fields on the background of a fluctuating spacetime volume. It is applied to formulate the stochastic Einstein equations with a perfect-fluid source. We investigate the particular case of a…

General Relativity and Quantum Cosmology · Physics 2017-09-06 Vladimir Dzhunushaliev , Hernando Quevedo

In this Letter, we study analytically the evolutions of the flat Friedmann-Lemaitre-Robertson-Walker (FLRW) universe and its linear perturbations in the framework of {\em the dressed metric approach} in loop quantum cosmology (LQC).…

General Relativity and Quantum Cosmology · Physics 2017-09-21 Tao Zhu , Anzhong Wang , Klaus Kirsten , Gerald Cleaver , Qin Sheng

The main objective of this manuscript is to investigate the bouncing cosmology in the background of $f(\mathcal{Q})$ gravity, where $\mathcal{Q}$ defines the non-metricity. For this purpose, we use the reconstruction approach and consider a…

General Relativity and Quantum Cosmology · Physics 2024-04-02 M. Sharif , M. Zeeshan Gul , Nusrat Fatima

We provide an analytical solution to the quantum dynamics of a flat Friedmann-Lema\^itre- Robertson-Walker model with a massless scalar field in the presence of a small and positive cosmological constant, in the context of Loop Quantum…

General Relativity and Quantum Cosmology · Physics 2020-02-06 Mercedes Martín-Benito , Rita B. Neves

We examine the dynamical behavior of matter coupled to gravity in the context of a linear Klein-Gordon equation coupled to a Friedman-Robertson-Walker metric. The resulting ordinary differential equations can be decoupled, the effect of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. Christodoulakis , C. Helias , P. G. Kevrekidis , I. G. Kevrekidis , G. O. Papadopoulos

Particle-antiparticle pairs are predicted by quantum field theory to appear as vacuum fluctuations. The model of the vacuum used here is postulated to have the following properties: To minimize the violation of conservation energy allowed…

Quantum Physics · Physics 2019-10-02 G. B. Mainland , Bernard Mulligan

In loop quantum cosmology, Friedmann-LeMaitre-Robertson-Walker (FLRW) space-times arise as well-defined approximations to specific \emph{quantum} geometries. We initiate the development of a quantum theory of test scalar fields on these…

General Relativity and Quantum Cosmology · Physics 2009-11-06 Abhay Ashtekar , Wojciech Kaminski , Jerzy Lewandowski

We review the quantum version of the linear Boltzmann equation, which describes in a non-perturbative fashion, by means of scattering theory, how the quantum motion of a single test particle is affected by collisions with an ideal…

Quantum Physics · Physics 2010-09-28 Bassano Vacchini , Klaus Hornberger

A spatially flat Friedmann-Robertson-Walker(FRW) cosmological model with generalized Chaplygin gas is studied in the context of scalar-metric formulation of cosmology. Schutz's mechanism for the perfect fluid is applied with generalized…

General Relativity and Quantum Cosmology · Physics 2011-06-24 Barun Majumder

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…

High Energy Physics - Phenomenology · Physics 2014-11-17 D. Boyanovsky , D. Cormier , H. J. de Vega , R. Holman , A. Singh , M. Srednicki

We examine Bousso's covariant entropy bound conjecture in the context of radiation filled, spatially flat, Friedmann-Robertson-Walker models. The bound is violated near the big bang. However, the hope has been that quantum gravity effects…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Abhay Ashtekar , Edward Wilson-Ewing

We measured the overall motion of Brownian particles suspended in water by a self-mixing thin-slice solid-state laser with extreme optical sensitivity. From the demodulated signal of laser intensity fluctuations through self-mixing…

The influence of measurement back action on electro-optic sampling of electromagnetic quantum fluctuations is investigated. Based on a cascaded treatment of the nonlinear interaction between a near-infrared coherent probe and the…

We investigate under which conditions we can expect to observe quantum brownian motion in a microscope. Using the fluctuation-dissipation theorem, we investigate quantum brownian motion in an ohmic bath, and estimate temporal and spatial…

Statistical Mechanics · Physics 2015-05-19 Lars Egil Helseth

We adapt the dual-null foliation to the functional Schr\"odinger representation of quantum field theory and study the behavior of quantum probes in plane-wave space-times near the null-singularity. A comparison between the Einstein-Rosen…

High Energy Physics - Theory · Physics 2022-10-03 Ivo Sachs , Marc Schneider , Maximilian Urban

Einstein-Smoluchowski diffusion, damped harmonic oscillations, and spatial decoherence are special cases of an elegant class of Markovian quantum Brownian motion models that is invariant under linear symplectic transformations. Here we…

Quantum Physics · Physics 2016-02-04 C. Jess Riedel

We analytically describe the decay to equilibrium of generic observables of a non-integrable system after a perturbation in the form of a random matrix. We further obtain an analytic form for the time-averaged fluctuations of an observable…

Quantum Physics · Physics 2019-06-05 Charlie Nation , Diego Porras

Quantum gravity phenomenology opens up the possibility of probing Planck scale physics. Thus, by exploiting the generic properties that a semiclassical state of the compound system fermions plus gravity should have, an effective dynamics of…

High Energy Physics - Theory · Physics 2009-11-07 J. Alfaro , H. A. Morales-Tecotl , L. F. Urrutia