English
Related papers

Related papers: Non-linearity and Non-Gaussianity through Phase In…

200 papers

We present measurements of the bispectrum of dark matter halos in numerical simulations with non-Gaussian initial conditions of the local type. We show, in the first place, that the overall effect of primordial non-Gaussianity on the halo…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Emiliano Sefusatti , Martin Crocce , Vincent Desjacques

The fluctuations generated by Inflation are nearly Gaussian in the simplest models, but may be non-Gaussian in more complex models, potentially leading to signatures in the late Universe. In particular, local type primordial non-Gaussianity…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-03 Mponeng Kopana , Sheean Jolicoeur , Roy Maartens

Various phase transitions in models for coupled charge-density waves are investigated by means of the $\epsilon$-expansion, mean-field theory, and Monte Carlo simulations. At zero temperature the effective action for the system with…

Strongly Correlated Electrons · Physics 2009-11-10 Minchul Lee , Eun-Ah Kim , Jong Soo Lim , M. Y. Choi

We present a new approach to gauge-invariant cosmological perturbations at second order, which is also covariant. We examine two cases in particular for a dust Friedman-Lemaitre-Robertson-Walker model of any curvature: we investigate…

Astrophysics · Physics 2014-10-13 Chris Clarkson

The determination of the inflationary energy scale represents one of the first step towards the understanding of the early Universe physics. The (very mild) non-Gaussian signals that arise from any inflation model carry information about…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-27 Nicola Bellomo , Nicola Bartolo , Raul Jimenez , Sabino Matarrese , Licia Verde

We perform cosmological N-body simulations with non-Gaussian initial conditions generated from two independent fields. The dominant contribution to the perturbations comes from a purely Gaussian field, but we allow the second field to have…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-25 Saroj Adhikari , Sarah Shandera , Neal Dalal

A mechanism for generating metric perturbations in inflationary models is considered. Long-wavelength inhomogeneities of light scalar fields in a decoupled sector may give rise to superhorizon fluctuations of couplings and masses in the…

High Energy Physics - Phenomenology · Physics 2009-07-24 Tomohiro Matsuda

In this paper, we model the bounce phase, stability, and the reconstruction of the universe by non-minimal kinetic coupling. In the process, we obtained importance information about the energy density and the matter pressure of the universe…

General Relativity and Quantum Cosmology · Physics 2026-02-10 Alireza Amani , A. S. Kubeka , E. Mahichi

Long-short mode coupling during inflation, encoded in the squeezed bispectrum of curvature perturbations, induces a dependence of the local, small-scale power spectrum on long-wavelength perturbations, leading to a scale-dependent halo…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Giovanni Cabass , Enrico Pajer , Fabian Schmidt

We revisit the method of cumulants for analysing dynamic light scattering data in particle sizing applications. Here the data, in the form of the time correlation function of scattered light, is written as a series involving the first few…

Soft Condensed Matter · Physics 2015-04-27 Alastair G. Mailer , Paul S. Clegg , Peter N. Pusey

Quantum non-Gaussian states of photons and phonons are conclusive and direct witnesses of higher-than-quadratic nonlinearities in optical and mechanical processes. Moreover, they are proven resources for quantum sensing, communication and…

Quantum Physics · Physics 2025-03-14 Lukáš Lachman , Radim Filip

The forthcoming Stage-IV experiments aim to map the large scale structure of the Universe at high precision. The scales explored require a relativistic description, in addition to statistical tools for their analysis. In this thesis, we…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-21 Rebeca Martinez-Carrillo

This is a review of models of inflation and of their predictions for the primordial non-Gaussianity in the density perturbations which are thought to be at the origin of structures in the Universe. Non-Gaussianity emerges as a key…

Astrophysics · Physics 2009-11-10 N. Bartolo , E. Komatsu , S. Matarrese , A. Riotto

Interferometric methods, renowned for their reliability and precision, play a vital role in phase imaging. Interferometry typically requires high coherence and stability between the measured and the reference beam. The presence of rapid…

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

We study the behavior of n-point functions of the primordial curvature perturbations, assuming our observed Universe is only a subset of a larger space with statistically homogeneous and isotropic perturbations. If the larger space has…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-25 Elliot Nelson , Sarah Shandera

We present a framework to compute non-Gaussian likelihoods for two-point correlation functions. The non-Gaussianity is most pronounced on large scales that will be well-measured by stage-IV weak-lensing surveys. We show how such a…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-09 Veronika Oehl , Tilman Tröster

Most biological signals are non-Gaussian, reflecting their origins in highly nonlinear physiological systems. A versatile set of techniques for studying non-Gaussian signals relies on the spectral representations of higher moments, known as…

Methodology · Statistics 2019-01-30 Christopher K. Kovach , Hiroyuki Oya , Hiroto Kawasaki

In the pursuit of primordial non-Gaussianities, we hope to access smaller scales across larger comoving volumes. At low redshift, the search for primordial non-Gaussianities is hindered by gravitational collapse, to which we often associate…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-08 Thomas Flöss , Matteo Biagetti , P. Daniel Meerburg

The initial conditions of cosmological simulations are commonly drawn from a Gaussian ensemble. The limited number of modes inside a simulation volume gives rise to statistical fluctuations known as \textit{sample variance}, limiting the…