搜索结果: 1-15 共查到“天文学 non-Gaussianity”相关记录16条 . 查询时间(0.062 秒)
We investigate density perturbations sourced by a curvaton with a generic energy potential. The key feature of a curvaton potential which deviates from quadratic is that the curvaton experiences a non...
Primordial Non-Gaussianity and Extreme-Value Statistics of Galaxy Clusters
Primordial Non-Gaussianity Extreme-Value Statistics Galaxy Clusters
2011/10/20
What is the size of the most massive object one expects to find in a survey of a given volume? In this paper, we present a solution to this problem using Extreme-Value Statistics. We calculate the pro...
We study the hybrid inflationary potential in a regime where the defect field is light, and more than 60 e-folds of accelerated expansion occur after the symmetry breaking transition. Using analytic a...
The inflaton-curvaton scenario in the MSSM and predictions for non-Gaussianity
inflaton-curvaton scenario MSSM predictions non-Gaussianity
2011/10/14
We provide a model in which both the inflaton and the curvaton are obtained from within the minimal supersymmetric Standard Model, with known gauge and Yukawa interactions. Since now both the inflaton...
Curvature perturbation spectra from waterfall transition, black hole constraints and non-Gaussianity
waterfall transition black hole constraints non-Gaussianity
2011/10/11
We carried out numerical calculations of a contribution of the waterfall field to the primordial curvature perturbation (on uniform density hypersurfaces) $\zeta$, which is produced during waterfall t...
Evolution of non-Gaussianity in multi-scalar field models
Infl ation Cosmological perturbation theory Physics of the early universe
2011/10/8
We study the evolution of non-Gaussianity in multiple-field inflationary models, focusing on three fundamental questions: (a) How is the sign and peak magnitude of the non-linearity parameter fNL rela...
Characterisation of the non-Gaussianity of radio and IR point-sources at CMB frequencies
ology: Cosmic Microwave Background, large scale structures Galaxiesstatistics, Infrared: galaxies Radio continuum: galaxies Methods: statistical
2011/10/8
The present study focuses on the characterisation of the non-Gaussianity produced by radio point-sources and, for the first time, by infrared sources in the frequency range of the CMB from 30 to 350 G...
Measuring primordial non-Gaussianity through weak lensing peak counts
Measuring primordial non-Gaussianity weak lensing peak counts
2011/1/11
We explore the possibility of detecting primordial non-Gaussianity of the local type using weak lensing peak counts. We measure the peak abundance in sets of simulated weak lensing maps corresponding ...
Galilean symmetry in the effective theory of inflation: new shapes of non-Gaussianity
effective theory of inflation new shapes of non-Gaussianity
2010/11/16
We study the consequences of imposing an approximate Galilean symmetry on the Effective Theory
of Inflation, the theory of small perturbations around the inflationary background. This approach allows...
Primordial non-Gaussianity in the Bispectrum of the Halo Density Field
Inflation Large Scale Structure Primordial non-Gaussianity
2010/11/11
The bispectrum vanishes for linear Gaussian elds and is thus a sensitive probe of non-
linearities and non-Gaussianities in the cosmic density eld. Hence, a detection of the bispectrum in the halo ...
We investigate the non-Gaussianity of primordial cosmological perturbations within our recently proposed holographic description of inflationary universes. We derive a holographic formula that determi...
By assuming the field seeding the curvature perturbations $ \zeta $ is a dynamically arising condensate, we are able to derive the relation $ f_{NL} ^2 \simeq 10^8 H / M_c $ between the non-Gaussianit...
Local non-Gaussianity in the Cosmic Microwave Background the Bayesian way
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/27
We introduce an exact Bayesian approach to search for non-Gaussianity of local type in Cosmic Microwave Background (CMB) radiation data. Using simulated CMB temperature maps, the newly developed techn...
Local stochastic non-Gaussianity and N-body simulations
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/22
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}).
The CMB Bispectrum, Trispectrum, non-Gaussianity, and the Cramer-Rao Bound
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/23
Minimum-variance estimators for the parameter fnl that quantifies local-model non-Gaussianity can be constructed from the cosmic microwave background (CMB) bispectrum (three-point function) and also f...