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Related papers: Non-Gaussianity in three fluid curvaton model

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We consider a class of multi-component hybrid inflation models whose evolution may be analytically solved under the slow-roll approximation. We call it multi-brid inflation (or $n$-brid inflation where $n$ stands for the number of inflaton…

Astrophysics · Physics 2009-10-09 Misao Sasaki

We compute the level of non-gaussianities produced by a cosmological bouncing phase in the minimal non-singular setup that lies within the context of General Relativity when the matter content consists of a simple scalar field with a…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Xian Gao , Marc Lilley , Patrick Peter

We extend the definition of non-adiabatic entropy production given for Markovian systems in [M. Esposito and C. Van den Broeck, Phys. Rev. Lett. 104 090601, (2010)], to arbitrary non-Markov ergodic dynamics. We also introduce a notion of…

Statistical Mechanics · Physics 2012-09-14 Reinaldo García-García

We show how to build a curvaton inflationary model motivated by scale-dependent non-Gaussianities of cosmological perturbations. In particular, we study the change of sign in the $f_{NL}$ parameter as a function of the curvaton field value…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 L. F. Guimarães , F. T. Falciano

We extend the formalism to calculate non-Gaussianity of primordial curvature perturbations produced by preheating in the presence of a light scalar field. The calculation is carried out in the separate universe approximation using the…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-31 Pulkit S. Ghoderao , Arttu Rajantie

The paper is devoted to the development of a microscopic description of the critical behavior of a cell fluid model with allowance for the contributions from collective variables with nonzero values of the wave vector. The mathematical…

Statistical Mechanics · Physics 2020-07-01 I. V. Pylyuk , O. A. Dobush

A nonsingular bouncing cosmology in which the scales of interest today exit the Hubble radius in a matter-dominated contracting phase yields an alternative to inflation for producing a scale-invariant spectrum of adiabatic cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2009-05-21 Yi-Fu Cai , Wei Xue , Robert Brandenberger , Xinmin Zhang

We consider the thermodynamic geometry of an ideal non-Abelian gas. We show that, for a certain value of the fractional parameter and at the relevant maximum value of fugacity, the thermodynamic curvature has a singular point. This…

Statistical Mechanics · Physics 2011-09-15 Behrouz Mirza , Hosein Mohammadzadeh

We consider constraints on the structure formation model based on non-Gaussian fluctuations generated during inflation, which have $\chi_m^2$ distributions. Using three data sets, the abundance of the clusters at $z=0$, moderate $z$ and the…

Astrophysics · Physics 2009-10-31 Kazuya Koyama , Jiro Soda , Atsushi Taruya

In the causal theory of relativistic dissipative fluid dynamics, there are conditions on the equation of state and other thermodynamic properties such as the second-order coefficients of a fluid that need to be satisfied to guarantee that…

Nuclear Theory · Physics 2008-11-26 Azwinndini Muronga

Large-scale clustering of highly biased tracers of large-scale structure has emerged as one of the best observational probes of primordial non-Gaussianity of the local type (i.e. f_{NL}^{local}). This type of non-Gaussianity can be…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Kendrick M. Smith , Marilena LoVerde

In writing a covariant effective action for single field inflation, one is allowed to add a Gauss-Bonnet and axion-type curvature couplings. These couplings represent modifications of gravity, and are the unique higher-curvature terms that…

High Energy Physics - Theory · Physics 2009-03-12 Samuel E. Vazquez

We study the evolution of the cosmological perturbations after inflation in curvaton models where the non-relativistic curvaton decays into both radiation and a cold dark matter component. We calculate the primordial curvature and…

Astrophysics · Physics 2009-11-10 Sujata Gupta , Karim A. Malik , David Wands

The condition of thermal equilibrium simplifies the theoretical treatment of fluctuations as found in the celebrated Einstein's relation between mobility and diffusivity for Brownian motion. Several recent theories relax the hypothesis of…

Statistical Mechanics · Physics 2014-04-10 Andrea Gnoli , Andrea Puglisi , Alessandro Sarracino , Angelo Vulpiani

Nonlocal quantum fluids emerge as dark-matter models and tools for quantum simulations and technologies. However, strongly nonlinear regimes, like those involving multi-dimensional self-localized solitary waves, are marginally explored for…

Pattern Formation and Solitons · Physics 2023-02-01 Claudio Conti

We derive semi-analytic formulae for the local bispectrum and trispectrum in general two-field inflation and provide a simple geometric recipe for building observationally allowed models with observable non-Gaussianity. We use the \delta N…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Courtney M. Peterson , Max Tegmark

Motivated by stochastic models of climate phenomena, the steady-state of a linear stochastic model with additive Gaussian white noise is studied. Fluctuation theorems for nonequilibrium steady-states provide a constraint on the character of…

Statistical Mechanics · Physics 2008-01-04 Jeffrey B. Weiss

Caustics in the dynamics of heavy particles in turbulence accelerate particle collisions. The rate $\mathscr{J}$ at which these singularities form depends sensitively on the Stokes number St, the non-dimensional inertia parameter. Exact…

Fluid Dynamics · Physics 2025-10-01 J. Meibohm , L. Sundberg , B. Mehlig , K. Gustavsson

After simplifying and improving the non-Gaussian formalism we developed in previous work, we derive a quantitative expression for the three-point correlator (bispectrum) of the curvature perturbation in general multiple-field inflation…

Astrophysics · Physics 2008-11-26 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

We study the distribution of the resistance fluctuations of biased resistor networks in nonequilibrium steady states. The stationary conditions arise from the competition between two stochastic and biased processes of breaking and recovery…

Statistical Mechanics · Physics 2011-02-17 C. Pennetta , E. Alfinito , L. Reggiani , S. Ruffo