English
Related papers

Related papers: Non-Gaussian Effects on Domain Growth

200 papers

We formulate the statistics of peaks of non-Gaussian random fields and implement it to study the sphericity of peaks. For non-Gaussianity of the local type, we present a general formalism valid regardless of how large the deviation from…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-03 Cristiano Germani , Mohammad Ali Gorji , Michiru Uwabo-Niibo , Masahide Yamaguchi

Derivation of two-time second-order correlation function by following approaches such as stochastic differential equation, coherent-state propagator, and quasi-statistical distribution function is presented. In the process, the time…

Quantum Physics · Physics 2024-06-18 Sintayehu Tesfa

It is known that in gravitational instability scenarios the nonlinear dynamics induces non-Gaussian features in cosmological density fields that can be investigated with perturbation theory. Here, I derive the expression of the joint…

Astrophysics · Physics 2011-05-23 F. Bernardeau

Non-linear interactions during inflation generate non-Gaussianities in the distribution of primordial curvature. In many theories, the physics is scale-invariant, such that the induced three-point function depends solely on a dimensionless…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-27 Oliver H. E. Philcox

We measure the halo bispectrum covariance in a large set of N-body simulations and compare it with theoretical expectations. We find a large correlation among (even mildly) squeezed halo bispectrum configurations. A similarly large…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-14 Matteo Biagetti , Lina Castiblanco , Jorge Noreña , Emiliano Sefusatti

We study the asymmetry in the two-point cross-correlation function of two populations of galaxies focusing in particular on the relativistic effects that include the gravitational redshift. We derive the cross-correlation function on small…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-25 Elena Giusarma , Shadab Alam , Hongyu Zhu , Rupert A. C. Croft , Shirley Ho

We study the effect of non-trivial sound speeds on local-type non-Gaussianity during multiple-field inflation. To this end, we consider a model of multiple-field DBI and use the deltaN formalism to track the super-horizon evolution of…

High Energy Physics - Theory · Physics 2012-08-07 Jon Emery , Gianmassimo Tasinato , David Wands

Recently, the primordial non-Gaussianity in the curvaton model has been predicted assuming sudden decay of the curvaton. We extend the calculation to non-instantaneous decay by employing delta N -formalism. The difference between the…

Astrophysics · Physics 2007-05-23 Jussi Valiviita , Misao Sasaki , David Wands

Primordial gravitational waves could be non-Gaussian, just like primordial scalar perturbations. Although the tensor two-point function has thus-far remained elusive, the three-point function could, in principle, be large enough to be…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-14 Oliver H. E. Philcox , Maresuke Shiraishi

We calculate curvature perturbations in the scenario in which the curvaton field decays into another scalar field via parametric resonance. As a result of a nonlinear stage at the end of the resonance, standard perturbative calculation…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-15 Alex Chambers , Sami Nurmi , Arttu Rajantie

The domain growth processes originating from noise-induced nonequilibrium phase transitions are analyzed, both for non-conserved and conserved dynamics. The existence of a dynamical scaling regime is established in the two cases, and the…

Condensed Matter · Physics 2009-10-31 M. Ibanes , J. Garcia-Ojalvo , R. Toral , J. M. Sancho

We compute non-Gaussianities in N-flation, a string motivated model of assisted inflation with quadratic, separable potentials and masses given by the Marcenko-Pastur distribution. After estimating parameters characterizing the bi- and…

High Energy Physics - Theory · Physics 2010-10-27 Diana Battefeld , Thorsten Battefeld

In the light-cone Fock state expansion of gauge theories, the influence of non-valence states may be significant in precision non-perturbative calculations. In two-dimensional gauge theories, it is shown how these states modify the…

High Energy Physics - Theory · Physics 2016-08-25 S. Dalley

If cosmic inflation suffered tiny time-dependent deviations from the slow-roll regime, these would induce the existence of small scale-dependent features imprinted in the primordial spectra, with their shapes and sizes revealing information…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Sander Mooij , Gonzalo A. Palma , Grigoris Panotopoulos , Alex Soto

Gaussian couplings of partial sum processes are derived for the high-dimensional regime $d=o(n^{1/3})$. The coupling is derived for sums of independent random vectors and subsequently extended to nonstationary time series. Our inequalities…

Probability · Mathematics 2022-03-08 Fabian Mies , Ansgar Steland

We study a non local approximation of the Gaussian perimeter, proving the Gamma convergence to the local one. Surprisingly, in contrast with the local setting, the halfspace turns out to be a volume constrained stationary point if and only…

Analysis of PDEs · Mathematics 2020-11-17 Antonio De Rosa , Domenico Angelo La Manna

We study the one-point probability distribution functions (PDFs) of the peculiar velocity and the density fluctuation in a cosmological fluid. Within the perturbative approach to the structure formation scenario, the effect of ``pressure''…

Astrophysics · Physics 2009-11-11 Takayuki Tatekawa

We propose a method to probe higher-order correlators of the primordial density field through the inhomogeneity of local non-Gaussian parameters, such as f_NL, measured within smaller patches of the sky. Correlators between n-point…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-28 Christian T. Byrnes , Sami Nurmi , Gianmassimo Tasinato , David Wands

We show that nonperturbative vacuum effects can produce a vacuum-driven transition from a matter-dominated universe to one in which the effective equation of state is that of radiation plus cosmological constant. The actual material content…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Leonard Parker , Alpan Raval

Quantum vacuum fluctuations tend to be strongly anti-correlated, which reduces their observable effects. However, time dependence can upset the cancellation of these anti-correlated fluctuations and greatly enhance their effects. This form…

General Relativity and Quantum Cosmology · Physics 2014-03-12 Victor Parkinson , L. H. Ford