Related papers: Fluctuation-dissipation relation in cosmic microwa…
One of the major problems in cosmology today is to explain the observed acceleration of the universe. The present observational data are consistent with the simplest solution to this problem, which is based on the vacuum energy. A decaying…
We report on experiments addressing the non-linear interaction between a nano-mechanical mode and position fluctuations. The Duffing non-linearity transduces the Brownian motion of the mode, and of other non-linearly coupled ones, into…
This paper presents a completely analytic treatment of cosmological fluctuations whose wavelength is small enough to come within the horizon well before the energy densities of matter and radiation become equal. This analysis yields a…
Non-linear evolution of density fluctuations yields secondary anisotropies in the cosmic microwave background (CMB), which are correlated with the same density fluctuations that can be measured by weak lensing (WL) surveys. We study the…
For 2442 galaxies of the catalog, compiled based on the NED, SDSS, and CATS survey data with redshifts z, > 0.3 we conducted an analysis of the amplitude of temperature fluctuations in the cosmic microwave background (CMB) in the points,…
In this review, we scrutinize historical and modern results on the linear response of dynamical systems to external perturbations with a particular emphasis on the celebrated relationship between fluctuations and dissipation expressed by…
Within the framework of density functional perturbation theory (DFPT), we implement and test a novel "metric wave" response-function approach. It consists in the reformulation of an acoustic phonon perturbation in the curvilinear frame that…
Fluctuation-dissipation relation ensures thermodynamic equilibrium of a particle immersed in a heat bath. We will show that, under certain circumstances, the fluctuation-dissipation relation fails to ensure equilibrium between the immersed…
It is shown that, in addition to the Thomson scattering, the absorption due to the electron-electron, electron-ion and the electron -atom collisions in a partially ionized cosmic plasma would also contribute to the optical depth of the…
We examine bounds on adiabatic and isocurvature density fluctuations from $\mu$-type spectral distortions of the cosmic microwave background (CMB). Studies of such distortion are complementary to CMB measurements of the spectral index and…
Since the measurements of COBE/FIRAS in the mid-90's we know that the energy spectrum of the cosmic microwave background (CMB) is extremely close to that of a perfect blackbody at an average temperature T0~2.726K. However, a number of…
Although the Fluctuation-Dissipation framework is a first step to get a quantum model for electrical noise, the merging of displacement and conduction currents into the sole current of a series notion like the resistance R(f) does not help…
The recent evidence for a stochastic gravitational wave background (GWB) in the nanohertz band, announced by pulsar timing array (PTA) collaborations around the world, has been posited to be sourced by either a population of supermassive…
Plasma turbulence, and edge density fluctuations in particular, can under certain conditions broaden the cross-section of injected microwave beams significantly. This can be a severe problem for applications relying on well-localized…
The study of thermodynamic properties of microscopic systems, such as a colloid in a fluid, has been of great interest to researchers since the discovery of the fluctuation theorem and associated laws of stochastic thermodynamics. However,…
The effect of a change of noise amplitudes in overdamped diffusive systems is linked to their unperturbed behavior by means of a nonequilibrium fluctuation-response relation. This formula holds also for systems with state-independent…
We derive a non-perturbative, closed, analytic equation for the non-linear power spectrum of cosmic density fluctuations. This result is based on our kinetic field theory (KFT) of cosmic structure formation and on evaluating particle…
The fluctuation-dissipation relation is usually formulated for a system interacting with a heat bath at finite temperature in the context of linear response theory, where only small deviations from the mean are considered. We show that for…
Weak lensing distortion of the background cosmic microwave background (CMB) temperature and polarization patterns by the foreground density fluctuations is well studied in the literature. We discuss the gravitational lensing modification to…
We examine the nonequilibrium dynamics of a self-interacting $\lambda\phi^4$ scalar field theory. Using a real time formulation of finite temperature field theory we derive, up to two loops and $O(\lambda^2)$, the effective equation of…