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The effect of quantum fluctuations on a nearly flat, nonrelativistic two-dimensional membrane with extrinsic curvature stiffness and tension is investigated. The renormalization group analysis is carried out in first-order perturbative…

Condensed Matter · Physics 2009-10-31 M. E. S. Borelli , H. Kleinert , Adriaan M. J. Schakel

The total energy of an eigenstate in a composite quantum system tends to be distributed equally among its constituents. We identify the quantum fluctuation around this equipartition principle in the simplest disordered quantum system…

Mathematical Physics · Physics 2023-12-21 Giorgio Cipolloni , László Erdős , Joscha Henheik , Oleksii Kolupaiev

We calculate the power spectrum of vacuum fluctuations of a generic scalar field in a quantum cosmological setting that is manifestly singularity-free. The power spectrum is given in terms of the usual scale invariant spectrum plus scale…

Astrophysics · Physics 2007-05-23 S. Hofmann , O. Winkler

Of indisputable relevance for non-equilibrium thermodynamics, fluctuations theorems have been generalized to the framework of quantum thermodynamics, with the notion of work playing a key role in such contexts. The typical approach consists…

Quantum Physics · Physics 2023-06-28 Thales Augusto Barbosa Pinto Silva , Renato Moreira Angelo

We develop the statistical mechanics of the Hopfield model in a transverse field to investigate how quantum fluctuations affect the macroscopic behavior of neural networks. When the number of embedded patterns is finite, the Trotter…

Condensed Matter · Physics 2009-10-28 Hidetoshi Nishimori , Yoshihiko Nonomura

It is shown, by considering the case of the harmonic oscillator, that quantum fluctuations may be the most significant contribution to the random walk of a single molecule. From this point, the controversy on the existence of a standard…

Quantum Physics · Physics 2010-01-05 Jean Paul Mbelek

Quantum systems with constraints are often considered in modern theoretical physcics. All realistic field models based on the idea of gauge symmetry are of this type. A partial case of constraints being linear in coordinate and momenta…

Mathematical Physics · Physics 2007-05-23 O. Yu. Shvedov

We derive an inequality relating the finite-frequency linear response and fluctuations of an observable in a physical system. The relation holds for arbitrary observables and perturbations in general Markovian dynamics, including over- and…

Statistical Mechanics · Physics 2025-10-20 Andreas Dechant

We study the fluctuations of the autocorrelation and autoresponse functions and, in particular, their variances and co-variance. In a first general part of the Article, we show the equivalence of the variance of the response function with…

Statistical Mechanics · Physics 2015-05-18 Federico Corberi , Eugenio Lippiello , Alessandro Sarracino , Marco Zannetti

A thermal model of kinetic friction is assigned to a classical loaded particle moving on a fluctuating smooth surface. A sinusoidal wave resembles surface fluctuations with a relaxation time. The Hamiltonian is approximated to the mean…

Mesoscale and Nanoscale Physics · Physics 2023-05-08 Rasoul Kheiri

Building on a model recently proposed by F. Calogero, we postulate the existence of a coherent, long--range universal tremor affecting any stable and confined classical dynamical system. Deriving the characteristic fluctuative unit of…

Quantum Physics · Physics 2015-06-26 Salvatore De Martino , Silvio De Siena , F. Illuminati

First-passage processes are pervasive across numerous scientific fields, yet a general framework for understanding their response to external perturbations remains elusive. While the fluctuation-dissipation theorem offers a complete linear…

Statistical Mechanics · Physics 2025-08-05 Tommer D. Keidar , Shlomi Reuveni

We analyze the Lattice Boltzmann method for the simulation of fluctuating hydrodynamics by Adhikari et al. [Europhys. Lett. 71, 473 (2005)] and find that it shows excellent agreement with theory even for small wavelengths as long as a…

Soft Condensed Matter · Physics 2016-08-24 Goetz Kaehler , Alexander Wagner

The quantum fluctuations of fields can exhibit subtle correlations in space and time. As the interval between a pair of measurements varies, the correlation function can change sign, signaling a shift between correlation and…

Quantum Physics · Physics 2024-12-05 Emily R. Taylor , Samuel Yencho , L. H. Ford

The quantum dynamics of fermionic or bosonic many-body systems following external excitation can be successfully studied using two-time nonequilibrium Green's functions (NEGF) or single-time reduced density matrix methods. Approximations…

Strongly Correlated Electrons · Physics 2022-07-12 Erik Schroedter , Jan-Philip Joost , Michael Bonitz

In this tutorial presentation, we give a comprehensive introduction into the Gutzwiller variational approach and its merger with the density functional theory. The merits of this method are illustrated by a discussion of results for…

Strongly Correlated Electrons · Physics 2012-07-30 Jörg Bünemann

Near field radiative heat transfer and dynamic Casimir forces are just two instances of topics of technological and fundamental interest studied via the formalism of fluctuational electrodynamics. From the perspective of experiment and…

Quantum Physics · Physics 2015-06-16 Vladyslav A. Golyk , Matthias Krüger , Mehran Kardar

We present and discuss a master equation blueprint for a generic class of quantum measurement feedback based models of friction. A desired velocity-dependent friction force is realized on average by random repeated applications of unsharp…

Quantum Physics · Physics 2023-04-13 Michael Gaida , Stefan Nimmrichter

By measuring a linear response function directly, such as the dynamic susceptibility, one can understand fundamental material properties. However, a fresh perspective can be offered by studying fluctuations. This can be related back to the…

Strongly Correlated Electrons · Physics 2021-05-04 L. Shen , M. Seaberg , E. Blackburn , J. J. Turner

Small quantum fluctuations in solitons described by the cubic-quintic nonlinear Schr\"{o}dinger equation (CQNLSE) are studied with the linear approximation. The cases of both self-defocusing and self-focusing quintic term are considered (in…

Quantum Physics · Physics 2007-05-23 Ray-Kuang Lee , Yinchieh Lai , Boris A. Malomed