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The thermovoltage of a chaotic quantum dot is measured using a current heating technique. The fluctuations in the thermopower as a function of magnetic field and dot shape display a non-Gaussian distribution, in agreement with simulations…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 S. F. Godijn , S. Moeller , H. Buhmann , L. W. Molenkamp , S. A. van Langen

Using the quantum information picture to describe the early universe as a time dependent quantum density matrix, with time playing the role of a stochastic variable, we compute the non-gaussian features in the distribution of primordial…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-19 Cesar Gomez , Raul Jimenez

Primordial non-Gaussianity is a crucial test of inflationary cosmology. We consider the impact of non-Gaussianity on the ionization power spectrum from 21 cm emission during the epoch of reionization. We focus on the power spectrum on large…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-30 Shahab Joudaki , Olivier Dore , Luis Ferramacho , Manoj Kaplinghat , Mario G. Santos

We propose a set of new statistics which can be extracted out of the angular distribution of the Fourier transform of the temperature anisotropies in the small field limit. They quantify generic non-Gaussian structure and complement the…

Astrophysics · Physics 2007-05-23 Pedro G. Ferreira

Standard results for the fluctuations of thermodynamic quantities are derived under the assumption of sampling identical systems that are in different, not fully equilibrated states. These results apply to fluctuations with time in a…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 R. A. Serota

We calculate the scale dependence of the bispectrum and trispectrum in (quasi) local models of non-Gaussian primordial density perturbations, and characterize this scale dependence in terms of new observable parameters. They can help to…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-12 Christian T. Byrnes , Mischa Gerstenlauer , Sami Nurmi , Gianmassimo Tasinato , David Wands

We argue that the typical energy density of a light scalar field should not be less than $H^4$ in the inflationary Universe. This requirement implies that the non-Gaussianity parameter $f_{NL}$ is typically bounded by the tensor-scalar…

High Energy Physics - Theory · Physics 2008-11-26 Qing-Guo Huang

Imaging thermal sources naturally yields Gaussian states at the receiver, raising the question of whether Gaussian measurements can perform optimally in quantum imaging. In this work, we establish no-go theorems on the performance of…

Quantum Physics · Physics 2025-08-15 Yunkai Wang , Sisi Zhou

If cosmological perturbations in our Hubble sized volume are nongaussian, then they will be coupled to any larger perturbation modes outside our Hubble volume. This has important consequences for modeling inflation: the scalar power…

High Energy Physics - Phenomenology · Physics 2014-02-14 Joseph Bramante

We propose a measure of non-Gaussianity for quantum states of a system of $n$ oscillator modes. Our measure is based on the quasi-probability $Q(\alpha), \alpha\in{\cal C}^n$. Since any measure of non-Gaussianity is necessarily an attempt…

Quantum Physics · Physics 2008-12-16 J. Solomon Ivan , M. Sanjay Kumar , R. Simon

Gaussian random fields pervade all areas of science. However, it is often the departures from Gaussianity that carry the crucial signature of the nonlinear mechanisms at the heart of diverse phenomena, ranging from structure formation in…

Statistical Mechanics · Physics 2015-06-05 T. H. Beuman , A. M. Turner , V. Vitelli

We investigate the possible effects on the evolution of perturbations in the inflationary epoch due to short distance physics. We introduce a suitable non local action for the inflaton field, suggested by Noncommutative Geometry, and…

High Energy Physics - Theory · Physics 2009-11-07 Fedele Lizzi , Gianpiero Mangano , Gennaro Miele , Marco Peloso

We use the local curvature to investigate the possible existence of non-Gaussianity/asymmetry in the WMAP data. Considering the full sky we find results which are consistent with the Gaussian assumption. However, strong non-Gaussian…

Astrophysics · Physics 2010-04-06 Frode K. Hansen , Paolo Cabella , Domenico Marinucci , Nicola Vittorio

We compute the matter bispectrum in the presence of primordial local non-Gaussianity over a wide range of scales, including the very small nonlinear ones. We use the Halo Model approach, considering non-Gaussian corrections to the halo…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 D. G. Figueroa , E. Sefusatti , A. Riotto , F. Vernizzi

Local non-Gaussianity, parametrized by $f_{\rm NL}$, introduces a scale-dependent bias that is strongest at large scales, precisely where General Relativistic (GR) effects also become significant. With future data, it should be possible to…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Marco Bruni , Robert Crittenden , Kazuya Koyama , Roy Maartens , Cyril Pitrou , David Wands

In this review, we discuss how non-Gaussianity of cosmological perturbations arises from inflation. After introducing the in-in formalism to calculate the $n$-point correlation function of quantum fields, we present the computation of the…

High Energy Physics - Theory · Physics 2014-11-20 Kazuya Koyama

We show that curvature perturbations acquire a scale invariant spectrum for any constant equation of state, provided the fluid has a suitably time-dependent sound speed. In order for modes to exit the physical horizon, and in order to solve…

High Energy Physics - Theory · Physics 2011-03-18 Justin Khoury , Federico Piazza

Motivated by the properties of early universe scenarios that produce observationally large local non-Gaussianity, we perform N-body simulations with non-Gaussian initial conditions from a generalized local ansatz. The bispectra are…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Sarah Shandera , Neal Dalal , Dragan Huterer

Non-Gaussian statistics in the distribution of large scale structure, and in temperature fluctuations of the cosmic microwave background, can be used to constrain inflationary models. Data on the cosmic microwave background from Planck…

General Relativity and Quantum Cosmology · Physics 2018-03-06 Nick Woods

By incorporating the holographic principle in a time-depending Lambda-term cosmology, new physical bounds on the arbitrary parameters of the model can be obtained. Considering then the dark energy as a purely geometric entity, for which no…

General Relativity and Quantum Cosmology · Physics 2009-11-11 J. P. Beltran Almeida , J. G. Pereira
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