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Related papers: Thermal fluctuations in viscous cosmology

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We analyse the large-scale coherence of the CMB anisotropy field with non-gaussian initial conditions usind 2-point function of the power fluctuations in the wavelet space. Employing the multivariate Edgeworth expansion (MEE) we constrain…

Astrophysics · Physics 2009-10-30 Lucia Popa

The effects that large scale fluctuations had on small scale isothermal modes at the epoch of recombination are analysed. We find that: (a) Albeit the fact that primordial fluctuations were at this epoch still well in the linear regime, a…

Astrophysics · Physics 2009-10-30 Nir J. Shaviv

Small thermodynamic systems exhibit peculiar behavior different from that observed in long-scale systems. Non-equilibrium processes taking place in those systems are strongly influenced by the presence of fluctuations which can be large.…

Statistical Mechanics · Physics 2007-05-23 J. M. Rubi

Based on recent perturbative and non-perturbative lattice calculations with almost quark flavors and the thermal contributions from photons, neutrinos, leptons, electroweak particles, and scalar Higgs bosons, various thermodynamic…

General Relativity and Quantum Cosmology · Physics 2021-02-26 Abdel Nasser Tawfik , Carsten Greiner

The non-equilibrium fluctuations of power flux in a fluidized granular media have been recently measured in an experiment [Phys. Rev. Lett. 92, 164301, 2004], which was announced to be a verification of the Fluctuation Relation (FR) by…

Statistical Mechanics · Physics 2007-05-23 A. Puglisi , P. Visco , A. Barrat , E. Trizac , F. van Wijland

The spectrum of thermal gravitational waves is obtained by including the high frequency thermal gravitons created from extra-dimensional effect and is a new feature of the spectrum. The amplitude and spectral energy density of gravitational…

General Relativity and Quantum Cosmology · Physics 2013-06-21 Basem Ghayour , P K Suresh

It has recently been shown that a Hagedorn phase of string gas cosmology can provide a causal mechanism for generating a nearly scale-invariant spectrum of scalar metric fluctuations, without the need for an intervening period of de Sitter…

High Energy Physics - Theory · Physics 2008-11-26 Robert H. Brandenberger , Ali Nayeri , Subodh P. Patil , Cumrun Vafa

Vacuum fluctuations of the electromagnetic field induce current fluctuations in resistively shunted Josephson junctions that are measurable in terms of a physical power spectrum. In this paper we investigate under which conditions vacuum…

Astrophysics · Physics 2008-11-26 Christian Beck , Michael C. Mackey

We continue to investigate possible signatures of a pre-inflationary anisotropic phase in two-point and three point correlation functions of the curvature perturbation for high-momentum modes which exit the horizon well after…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Anindya Dey , Ely D. Kovetz , Sonia Paban

We present the results of a numerical investigation of three-dimensional decaying turbulence with statistically homogeneous and anisotropic initial conditions. We show that at large times, in the inertial range of scales: (i) isotropic…

Chaotic Dynamics · Physics 2007-05-23 L. Biferale , G. Boffetta , A. Celani , A. Lanotte , F. Toschi , M. Vergassola

Examining the reverse evolution of the universe from the present, long before reaching Planck density dynamics one expects major modifications from the de-coherent thermal equations of state, suggesting a prior phase that has macroscopic…

Astrophysics · Physics 2007-05-23 James V. Lindesay , H. Pierre Noyes

The acoustic peak in the CMB power spectrum is sensitive to causal processes and cosmological parameters in the early universe up to the time of last scattering. We provide limits on correlated spatial variations of the peak height and peak…

Astrophysics · Physics 2009-11-10 Evan P. Donoghue , John F. Donoghue

Nonlinear effects are crucial in order to compute the cosmological matter power spectrum to the accuracy required by future generation surveys. Here, a new approach is presented, in which the power spectrum, the bispectrum and higher order…

Astrophysics · Physics 2009-11-13 Massimo Pietroni

Matrix theory is a proposed non-perturbative definition of superstring theory in which space is emergent. Recently, it was shown that space-time can emerge with a scale-invariant spectrum of cosmological perturbations which is sourced by…

High Energy Physics - Theory · Physics 2023-04-21 Samuel Laliberte , Suddhasattwa Brahma

The viscous Cardassian cosmology is discussed, assuming that there is a bulk viscosity in the cosmic fluid. The dynamical analysis indicates that there exists a singular curve in the phase diagram of viscous Cardassian model. In the viscous…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Chang-Bo Sun , Jia-Ling Wang , Xin-Zhou Li

Magnetic field fluctuations in the vicinity of the Earth's bow shock have been investigated with the aim to characterize the intermittent behaviour of strong plasma turbulence. The observed small-scale intermittency may be the signature of…

comp-gas · Physics 2020-01-29 T. Dudok de Wit , V. V. Krasnosel'skikh

We measure the power spectrum of the density distribution of a freely expanding 2D degenerate Bose gas, where irregular density modulations gradually develop due to the initial phase fluctuations in the sample. The spectrum has an…

Quantum Gases · Physics 2013-04-02 Jae-yoon Choi , Sang Won Seo , Woo Jin Kwon , Yong-il Shin

In this paper, we calculate the spectrum of scalar field fluctuations in a bouncing, asymptotically flat Universe, and investigate the dependence of the result on changes in the physics on length scales shorter than the Planck length which…

High Energy Physics - Theory · Physics 2009-11-07 Robert H Brandenberger , Sergio E. Joras , Jerome Martin

In ultracold gases many experiments use atom imaging as a basic observable. The resulting image is averaged over a number of realizations and mostly only this average is used. Only recently the noise has been measured to extract physical…

Statistical Mechanics · Physics 2015-05-13 G. E. Astrakharchik , R. Combescot , L. P. Pitaevskii

We investigate the thermal instability of a smooth equilibrium state, in which the density function satisfies Schwarzschild's (instability) condition, to a compressible heat-conducting viscous flow without heat conductivity in the presence…

Analysis of PDEs · Mathematics 2019-02-15 Fei Jiang