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The weak lensing power spectrum carries cosmological information via its dependence on the growth of structure and on geometric factors. Since much of the cosmological information comes from scales affected by nonlinear clustering,…

天体物理学 · 物理学 2010-11-02 Masahiro Takada , Bhuvnesh Jain

We generalize the local model of primordial non-Gaussianity by promoting the parameter fNL to a general scale-dependent function fNL(k). We calculate the resulting bispectrum and the effect on the bias of dark matter halos, and thus the…

宇宙学与河外天体物理 · 物理学 2011-01-18 Adam Becker , Dragan Huterer , Kenji Kadota

We investigate non-Gaussianity in general single field models without assuming slow-roll conditions or the exact scale-invariance of the scalar power spectrum. The models considered include general single field inflation (e.g. DBI and…

宇宙学与河外天体物理 · 物理学 2011-05-13 Johannes Noller , Joao Magueijo

The geological systems such as petroleum reservoirs is investigated by the entropy introduced by Tsallis and multiplicative hierarchical cascade model. When non-Gaussianity appears, it is sign of uncertainty and phase transition, which…

数据分析、统计与概率 · 物理学 2019-11-12 Z. Koohi lai , S. Vasheghani Farahani , G. R. Jafari

We study the significance of non-Gaussianity in the likelihood of weak lensing shear two-point correlation functions, detecting significantly non-zero skewness and kurtosis in one-dimensional marginal distributions of shear two-point…

宇宙学与河外天体物理 · 物理学 2020-11-11 Chien-Hao Lin , Joachim Harnois-Déraps , Tim Eifler , Taylor Pospisil , Rachel Mandelbaum , Ann B. Lee , Sukhdeep Singh

The Universe may harbor relics of the post-inflationary epoch in the form of a network of self-ordered scalar fields. Such fossils, while consistent with current cosmological data at trace levels, may leave too weak an imprint on the cosmic…

宇宙学与河外天体物理 · 物理学 2014-11-20 Daniel G. Figueroa , Robert R. Caldwell , Marc Kamionkowski

Quantum non-Gaussianity is a key resource for quantum advantage in continuous-variable systems. We introduce a general framework to quantify non-Gaussianity based on correlation generation: two copies of a state become correlated at a…

量子物理 · 物理学 2025-08-28 Oliver Hahn , Ryuji Takagi

We analyze the shape and amplitude of oscillatory features in the primordial power spectrum and non-Gaussianity induced by periodic production of heavy degrees of freedom coupled to the inflaton $\phi$. We find that non-adiabatic production…

高能物理 - 理论 · 物理学 2017-11-15 Raphael Flauger , Mehrdad Mirbabayi , Leonardo Senatore , Eva Silverstein

Gaussian process is a theoretically appealing model for nonparametric analysis, but its computational cumbersomeness hinders its use in large scale and the existing reduced-rank solutions are usually heuristic. In this work, we propose a…

机器学习 · 统计学 2015-11-25 Leo L. Duan , Xia Wang , Rhonda D. Szczesniak

Standard present day large-scale structure (LSS) analyses make a major assumption in their Bayesian parameter inference --- that the likelihood has a Gaussian form. For summary statistics currently used in LSS, this assumption, even if the…

宇宙学与河外天体物理 · 物理学 2019-03-06 ChangHoon Hahn , Florian Beutler , Manodeep Sinha , Andreas Berlind , Shirley Ho , David W. Hogg

Gaussian processes (GPs) are commonplace in spatial statistics. Although many non-stationary models have been developed, there is arguably a lack of flexibility compared to equipping each location with its own parameters. However, the…

机器学习 · 统计学 2018-07-19 Leo L. Duan , Xia Wang , Rhonda D. Szczesniak

Enormous information about interactions is contained in the non-Gaussianities of the primordial curvature perturbations, which are essential to break the degeneracy of inflationary models. We study the primordial bispectra for G-inflation…

宇宙学与河外天体物理 · 物理学 2021-04-21 Fengge Zhang , Yungui Gong , Jiong Lin , Yizhou Lu , Zhu Yi

We study the sample variance of the matter power spectrum for the standard Lambda Cold Dark Matter universe. We use a total of 5000 cosmological N-body simulations to study in detail the distribution of best-fit cosmological parameters and…

We derive the exact relationship, including all non-linearities, between real-space and redshift-space two-point statistics through the pairwise velocity distribution function. We show using numerical simulations that the pairwise velocity…

天体物理学 · 物理学 2009-11-10 Roman Scoccimarro

We investigate the noncommutative effect on the non-Gaussianities of primordial cosmological perturbation. In the lowest order of string length and slow-roll parameter, we find that in the models with small speed of sound the noncommutative…

天体物理学 · 物理学 2008-12-18 Kejie Fang , Bin Chen , Wei Xue

Gaussian process regression is a powerful Bayesian nonlinear regression method. Recent research has enabled the capture of many types of observations using non-Gaussian likelihoods. To deal with various tasks in spatial modeling, we benefit…

机器学习 · 统计学 2025-08-26 Yuta Shikuri

We propose two methods for generating non-Gaussian maps with fixed power spectrum and bispectrum. The first makes use of a recently proposed rigorous, non-perturbative, Bayesian framework for generating non-Gaussian distributions. The…

天体物理学 · 物理学 2009-11-06 Carlo R. Contaldi , Joao Magueijo

We address realistic schemes for the generation of non-Gaussian states of light based on conditional intensity measurements performed on correlated bipartite states. We consider both quantum and classically correlated states and different…

Constraints on cosmological parameters from large-scale structure have traditionally been obtained from two-point statistics. However, non-linear structure formation renders these statistics insufficient in capturing the full information…

宇宙学与河外天体物理 · 物理学 2017-11-22 Alex Hall , Alexander Mead

We present some nonparametric methods for graphical modeling. In the discrete case, where the data are binary or drawn from a finite alphabet, Markov random fields are already essentially nonparametric, since the cliques can take only a…

机器学习 · 统计学 2013-01-08 John Lafferty , Han Liu , Larry Wasserman