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The probability distribution function (PDF) of the mass surface density is an essential characteristic of the structure of molecular clouds or the interstellar medium in general. Observations of the PDF of molecular clouds indicate a…

星系天体物理 · 物理学 2015-06-18 Joerg Fischera

Cosmological large-scale structure analyses based on two-point correlation functions often assume a Gaussian likelihood function with a fixed covariance matrix. We study the impact on cosmological parameter estimation of ignoring the…

宇宙学与河外天体物理 · 物理学 2019-03-21 Darsh Kodwani , David Alonso , Pedro Ferreira

The variance--covariance matrix plays a central role in the inferential theories of high-dimensional factor models in finance and economics. Popular regularization methods of directly exploiting sparsity are not directly applicable to many…

统计方法学 · 统计学 2012-03-15 Jianqing Fan , Yuan Liao , Martina Mincheva

The probability distribution function (PDF) of the mass surface density of molecular clouds provides essential information about the structure of molecular cloud gas and condensed structures out of which stars may form. In general, the PDF…

星系天体物理 · 物理学 2015-06-22 Jörg Fischera

Accurate and precise covariance matrices will be important in enabling planned cosmological surveys to detect new physics. Standard methods imply either the need for many N-body simulations in order to obtain an accurate estimate, or a…

宇宙学与河外天体物理 · 物理学 2018-12-13 Alex Hall , Andy Taylor

Line-intensity mapping (LIM) is quickly attracting attention as an alternative technique to probe large-scale structure and galaxy formation and evolution at high redshift. LIM one-point statistics are motivated because they provide access…

宇宙学与河外天体物理 · 物理学 2024-03-06 José Luis Bernal

At any given scale, 3$\times$2-point statistics extract only three numbers from the joint distribution of the cosmic matter density and galaxy density fluctuations: their variances and their covariance. It is well known that the full shape…

宇宙学与河外天体物理 · 物理学 2026-01-07 Oliver Friedrich , Lina Castiblanco , Anik Halder , Cora Uhlemann

This paper investigates the cross-correlations across multiple climate model errors. We build a Bayesian hierarchical model that accounts for the spatial dependence of individual models as well as cross-covariances across different climate…

应用统计 · 统计学 2012-03-02 Huiyan Sang , Mikyoung Jun , Jianhua Z. Huang

We study the one-point probability distribution function (PDF) for matter density averaged over spherical cells. The leading part to the PDF is defined by spherical collapse dynamics, whereas the next-to-leading part comes from the…

宇宙学与河外天体物理 · 物理学 2023-08-08 Anton Chudaykin , Mikhail M. Ivanov , Sergey Sibiryakov

Extending previous studies, we derive generic predictions for lower order cumulants and their correlators for individual tomographic bins as well as between two different bins. We derive the corresponding one- and two-point joint…

宇宙学与河外天体物理 · 物理学 2015-06-03 Dipak Munshi , Peter Coles , Martin Kilbinger

We present a new calculation for the evolution of the 1-point Probability Distribution Function (PDF) of the cosmological density field based on an exact statistical treatment. Using the Chapman-Kolmogorov equation and second-order Eulerian…

天体物理学 · 物理学 2009-10-31 Andrew Taylor , Peter Watts

This paper outlines an approach to the approximation of probability density functions by quadratic forms of weighted orthonormal basis functions with positive semi-definite Hermitian matrices of unit trace. Such matrices are called…

概率论 · 数学 2016-11-17 Igor G. Vladimirov

Physics-based covariance models provide a systematic way to construct covariance models that are consistent with the underlying physical laws in Gaussian process analysis. The unknown parameters in the covariance models can be estimated…

统计计算 · 统计学 2023-03-20 Yian Chen , Mihai Anitescu

The likelihood function for cosmological parameters, given by e.g. weak lensing shear measurements, depends on contributions to the covariance induced by the nonlinear evolution of the cosmic web. As nonlinear clustering to date has only…

宇宙学与河外天体物理 · 物理学 2019-02-26 Robert Reischke , Alina Kiessling , Björn Malte Schäfer

Weak lensing measurements are starting to provide statistical maps of the distribution of matter in the universe that are increasingly precise and complementary to cosmic microwave background maps. The probability distribution (PDF)…

天体物理学 · 物理学 2009-11-10 Tong-Jie Zhang , Ue-Li Pen

We use the Delaunay Tessellation Field Estimator (DTFE) to study the one-point density distribution functions of the Millennium (MS) and Millennium-II (MS-II) simulations. The DTFE technique is based directly on the particle positions,…

宇宙学与河外天体物理 · 物理学 2015-06-12 Biswajit Pandey , Simon D. M. White , Volker Springel , Raul Angulo

Random processes play a crucial role in scientific research, often characterized by distribution functions or probability density functions (PDFs). These PDFs serve as essential approximations of the actual and frequently undisclosed…

统计方法学 · 统计学 2023-06-06 Nico Schick

We examine the cosmological information available from the 1-point probability distribution (PDF) of the weak-lensing convergence field, utilizing fast L-PICOLA simulations and a Fisher analysis. We find competitive constraints in the…

宇宙学与河外天体物理 · 物理学 2017-09-20 Kenneth Patton , Jonathan Blazek , Klaus Honscheid , Eric Huff , Peter Melchior , Ashley J. Ross , Eric Suchyta

In cosmic shear likelihood analyses the covariance is most commonly assumed to be constant in parameter space. Therefore, when calculating the covariance matrix (analytically or from simulations), its underlying cosmology should not…

天体物理学 · 物理学 2015-05-13 Tim Eifler , Peter Schneider , Jan Hartlap

An accurate covariance matrix is essential for obtaining reliable cosmological results when using a Gaussian likelihood. In this paper we study the covariance of pseudo-$C_\ell$ estimates of tomographic cosmic shear power spectra. Using two…