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We extend previous work on quantum stress tensor operators which have been averaged over finite time intervals to include averaging over finite regions of space as well. The space and time averaging can be viewed as describing a measurement…

High Energy Physics - Theory · Physics 2020-01-22 Christopher J. Fewster , L. H. Ford

We consider a quasi-periodically identified conical spacetime, like the one of a cosmic string or disclination, to investigate nonzero averaged quantum vacuum fluctuations effects on the energy-momentum tensor and induced current density…

High Energy Physics - Theory · Physics 2020-08-26 K. E. L. de Farias , H. F. Santana Mota

In the weak field approximation, the nonsymmetric gravitational theory has, in addition to the Newtonian gravitational potential, a Yukawa potential produced by the exchange of a spin $1^+$ boson between fermions. If the range $r_0$ is of…

Astrophysics · Physics 2015-06-24 J. W. Moffat

We consider the classical stochastic fluctuations of spacetime geometry induced by quantum fluctuations of massless non-conformal matter fields in the Early Universe. To this end, we supplement the stress-energy tensor of these fields with…

General Relativity and Quantum Cosmology · Physics 2008-11-26 E. Calzetta , A. Campos , E. Verdaguer

We introduce a semiclassical Einstein-Langevin equation as a consistent dynamical equation for a first order perturbative correction to semiclassical gravity. This equation includes the lowest order quantum stress-energy fluctuations of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Rosario Martin , Enric Verdaguer

We consider the effects of the quantum stress tensor fluctuations of a conformal field in generating gravity waves in inflationary models. We find a non-scale invariant, non-Gaussian contribution which depends upon the total expansion…

General Relativity and Quantum Cosmology · Physics 2011-12-08 Chun-Hsien Wu , Jen-Tsung Hsiang , L. H. Ford , Kin-Wang Ng

We present a systematic treatment of non-Gaussianity in stochastic systems using the Schwinger-Keldysh effective field theory framework, in which the non-Gaussianity is realized as nonlinear terms in the fluctuation field. We establish two…

High Energy Physics - Theory · Physics 2024-02-15 Shu Lin , Yanyan Bu , Chang Lei

It is generally expected that quantum gravity affects the structure of space-time by introducing stochastic fluctuations in the geometry, and, ultimately, in the measurements of four-distances and four-momenta.These fluctuations may induce…

Astrophysics · Physics 2007-05-23 R. Aloisio , P. Blasi , A. Galante , P. L. Ghia , A. F. Grillo

A considerable number of systems have recently been reported in which Brownian yet non-Gaussian dynamics was observed. These are processes characterised by a linear growth in time of the mean squared displacement, yet the probability…

Statistical Mechanics · Physics 2018-11-26 V. Sposini , A. V. Chechkin , F. Seno , G. Pagnini , R. Metzler

In the weak field approximation, the nonsymmetric gravitational theory (NGT) has, in addition to the Newtonian gravitational potential, a Yukawa-like potential produced by the exchange of a spin $1^+$ boson between fermions. If the range…

Astrophysics · Physics 2010-11-30 J. W. Moffat , I. Yu. Sokolov

It is well known that in quantum gravity, the very geometry of space and time is subject to continual fluctuation. The mathematical formulation for this old theory is still lacking. This article formulates this more than forty-year-old…

General Relativity and Quantum Cosmology · Physics 2024-09-27 Behzad Tajahmad

We discuss the energy distribution of free-electron Fermi-gas, a problem with a textbook solution of Gaussian energy fluctuations in the limit of a large system. We find that for a small system, characterized solely by its heat capacity…

Mesoscale and Nanoscale Physics · Physics 2016-09-21 Jukka P. Pekola , Paolo Muratore-Ginanneschi , Antti Kupiainen , Yuri M. Galperin

The dynamics of a one-dimensional stochastic model is studied in presence of an absorbing boundary. The distribution of fluctuations is analytically characterized within the generalized van Kampen expansion, accounting for higher order…

Statistical Mechanics · Physics 2015-05-28 Claudia Cianci , Francesca Di Patti , Duccio Fanelli

We analyze the non--Gaussian primordial fluctuations which are inescapably contributed by scalar fields $\Phi$ with vanishing expectation values, $\langle\Phi\rangle=0$, present during inflation in addition to the inflaton field. For…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Harald F. Muller , Christoph Schmid

We address the experimentally observed non-Gaussian fluctuations for the energy injected into a closed turbulent flow at fixed Reynolds number. We propose that the power fluctuations mirror the internal kinetic energy fluctuations. Using a…

Statistical Mechanics · Physics 2007-05-23 B. Portelli , P. C. W. Holdsworth , J. -F. Pinton

Semiclassical Einstein-Langevin equations for arbitrary small metric perturbations conformally coupled to a massless quantum scalar field in a spatially flat cosmological background are derived. Use is made of the fact that for this problem…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Antonio Campos , Enric Verdaguer

The gravitational potential and the gravitational rotation field generated by a thin-disk mass distribution with exponential density are considered in the case when the force between any two mass elements is not the usual Newtonian one, but…

Astrophysics · Physics 2007-05-23 Carlos Rodrigo-Blanco

In this paper we numerically examine the connection of the Gallavotti-Cohen fluctuation formula and the functional form of the corresponding probability density function in the field driven Lorentz gas thermostated by the Gaussian…

Chaotic Dynamics · Physics 2007-05-23 M. Dolowschiak , Z. Kovacs

We summarize several aspects of recent work on quantum stress tensor fluctuations and their role in driving fluctuations of the gravitational field. The role of correlations and anticorrelations is emphasized. We begin with a review of the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. H. Ford , Chun-Hsien Wu

In the context of semiclassical gravity, the semiclassical Einstein equation is often invoked when backreaction of quantum matter/fields on the spacetime is at stake. It is expected to hold when quantum fluctuations are small. Yet, it is…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Gustavo Schranck Habermann , Daniel A. Turolla Vanzella