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Related papers: Thermal non-Gaussianity in holographic cosmology

200 papers

We investigate the clustering of halos in cosmological models starting with general local-type non-Gaussian primordial fluctuations. We employ multiple Gaussian fields and add local-type non-Gaussian corrections at arbitrary order to cover…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Takahiro Nishimichi

In this note, we revisit the thermal fluctuations generated during bouncing cosmology, taking Unruh effect into account. We find that due to the additional effect on temperature, the dependence of power spectrum on $k$ will get corrected…

High Energy Physics - Theory · Physics 2010-04-15 Taotao Qiu

Light scalars may be ubiquitous in nature, and their quantum fluctuations can produce large non-Gaussianity in the cosmic microwave background temperature anisotropy. The non-Gaussianity may be accompanied with a small admixture of…

We generalize a recently proposed mechanism for the origin of primordial metric perturbations in inflationary models. Quantum fluctuations of light scalar fields during inflation give rise to super-horizon fluctuations of masses and…

Astrophysics · Physics 2010-04-06 Gia Dvali , Andrei Gruzinov , Matias Zaldarriaga

Noncommutative phase-space and its effects have been studied in different settings in physics, in order to unveil a better understanding of phase-space structures. Here, we use the thermal diffusion approach to study how noncommutative…

Quantum Physics · Physics 2019-09-16 Jonas F. G. Santos

We calculate the contribution of the fluctuations with the thermal origin to the inflationary nonGaussianity. We find that even a small component of radiation can lead to a large nonGaussianity. We show that this thermal nonGaussianity…

High Energy Physics - Theory · Physics 2009-12-15 Bin Chen , Yi Wang , Wei Xue

We develop a formalism to study non-Gaussianity in both curvature and isocurvature perturbations. It is shown that non-Gaussianity in the isocurvature perturbation between dark matter and photons leaves distinct signatures in the CMB…

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

What if Big Bang was hot from its very inception? This is possible in a bimetric theory where the source of fluctuations is thermal, requiring the model to live on a critical boundary in the space of parameters and can be realized when an…

High Energy Physics - Theory · Physics 2022-07-20 Maria Mylova , Marianthi Moschou , Niayesh Afshordi , João Magueijo

We apply the holographic principle in the cosmological context through the nonadditive Tsallis entropy, used to describe the thermodynamic properties of nonstandard statistical systems such as the gravitational ones. Assuming the future…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Rocco D'Agostino

We investigated evolution of metric and density perturbations for Tsallis model of holographic dark energy with energy density $\sim L^{2\gamma - 4}$, where $L$ is length of event horizon or inverse Hubble parameter and $\gamma$ is…

General Relativity and Quantum Cosmology · Physics 2025-08-25 Artyom V. Astashenok , Alexander S. Tepliakov

We use numerical simulations of a (480 Mpc/h)^3 volume to show that the distribution of peak heights in maps of the temperature fluctuations from the kinematic and thermal Sunyaev-Zeldovich effects will be highly non-Gaussian, and very…

Astrophysics · Physics 2009-11-06 Naoki Yoshida , Ravi K. Sheth , Antonaldo Diaferio

In this paper, we suppose that the universe begins in a holographic thermal equilibrium phase with the diverged correlation length, and the phase transition to the radiation phase of standard cosmology goes with the abrupt reducing of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yun-Song Piao

Whilst current observational evidence favors a close-to-Gaussian spectrum of primordial perturbations, there exist many models of the early Universe that predict this distribution to have exponentially enhanced or suppressed tails. In this…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 William R. Coulton , Oliver H. E. Philcox , Francisco Villaescusa-Navarro

The late-time effect of primordial non-Gaussianity offers a window into the physics of inflation and the very early Universe. In this work we study the consequences of a particular class of primordial non-Gaussianity that is fully…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 G. A. Peña , G. N. Candlish

We compute the spectrum of cosmological perturbations in a scenario in which inflation is driven by radiation in a non-commutative space-time. In this scenario, the non-commutativity of space and time leads to a modified dispersion relation…

High Energy Physics - Theory · Physics 2010-10-27 Seoktae Koh , Robert H. Brandenberger

The primary science driver for 3D galaxy surveys is their potential to constrain cosmological parameters. Forecasts of these surveys' effectiveness typically assume Gaussian statistics for the underlying matter density, despite the fact…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-27 Andrew Repp , István Szapudi , Julien Carron , Melody Wolk

In the standard picture of structure formation, initially random-phase fluctuations are amplified by non-linear gravitational instability to produce a final distribution of mass which is highly non-Gaussian and has highly coupled Fourier…

Astrophysics · Physics 2009-10-31 Peter Coles , Lung-Yih Chiang

We investigate the effect of primordial non-Gaussianity of the local f_NL type on the auto- and cross-power spectrum of dark matter haloes using simulations of the LCDM cosmology. We perform a series of large N-body simulations of both…

Astrophysics · Physics 2015-05-13 Vincent Desjacques , Uros Seljak , Ilian T. Iliev

We consider a quantum system with $N$ degrees of freedom which is classically chaotic. When $N$ is large, and both $\hbar$ and the quantum energy uncertainty $\Delta E$ are small, quantum chaos theory can be used to demonstrate the…

chao-dyn · Physics 2009-10-28 Mark Srednicki