English
Related papers

Related papers: On combining estimated and analytic covariance mat…

200 papers

Making cosmological inferences from the observed galaxy clustering requires accurate predictions for the mean clustering statistics and their covariances. Those are affected by cosmic variance -- the statistical noise due to the finite…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Anatoly Klypin , Francisco Prada , Joyce Byun

This paper proposes using a sparse-structured multivariate Gaussian to provide a closed-form approximator for the output of probabilistic ensemble models used for dense image prediction tasks. This is achieved through a convolutional neural…

Computer Vision and Pattern Recognition · Computer Science 2022-03-30 Ivor J. A. Simpson , Sara Vicente , Neill D. F. Campbell

This paper studies fundamental aspects of modelling data using multivariate Watson distributions. Although these distributions are natural for modelling axially symmetric data (i.e., unit vectors where $\pm \x$ are equivalent), for…

Computation · Statistics 2012-05-28 Suvrit Sra , Dmitrii Karp

We develop an econometric framework integrating heavy-tailed Student's $t$ distributions with behavioral probability weighting while preserving infinite divisibility. Using 432{,}752 observations across 86 assets (2004--2024), we…

Mathematical Finance · Quantitative Finance 2025-11-21 Akash Deep , Svetlozar T. Rachev , Frank J. Fabozzi

The classical stochastic model of cosmology recently developed by us is reconsidered. In that approach the parameter $w$ defined by the equation of state $p=w{\rho}$ was taken to be fluctuating with mean zero and we compared the theoretical…

Astrophysics · Physics 2009-11-07 Moncy V. John , C. Sivakumar , K. Babu Joseph

We study the problem of computationally efficient robust estimation of the covariance/scatter matrix of elliptical distributions -- that is, affine transformations of spherically symmetric distributions -- under the strong contamination…

Data Structures and Algorithms · Computer Science 2025-04-15 Gleb Novikov

Student's $t$ statistic is finding applications today that were never envisaged when it was introduced more than a century ago. Many of these applications rely on properties, for example robustness against heavy tailed sampling…

Methodology · Statistics 2010-01-25 Aurore Delaigle , Peter Hall , Jiashun Jin

We present a numerically cheap approximation to super-sample covariance (SSC) of large scale structure cosmological probes, first in the case of angular power spectra. It necessitates no new elements besides those used for the prediction of…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-17 Fabien Lacasa , Julien Grain

In optimal covariance cleaning theory, minimizing the Frobenius norm between the true population covariance matrix and a rotational invariant estimator is a key step. This estimator can be obtained asymptotically for large covariance…

Information Theory · Computer Science 2023-05-01 Christian Bongiorno , Marco Berritta

Many applications of Gaussian random fields and Gaussian random processes are limited by the computational complexity of evaluating the probability density function, which involves inverting the relevant covariance matrix. In this work, we…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-26 Theodor Bjorkmo , M. C. David Marsh

This paper tackles the problem of robust covariance matrix estimation when the data is incomplete. Classical statistical estimation methodologies are usually built upon the Gaussian assumption, whereas existing robust estimation ones assume…

The covariance matrix of the matter power spectrum is a key element of the statistical analysis of galaxy clustering data. Independent realisations of observational measurements can be used to sample the covariance, nevertheless statistical…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-14 Linda Blot , Pier Stefano Corasaniti , Luca Amendola , Thomas D. Kitching

To estimate cosmological parameters from a given dataset, we need to construct a likelihood function, which sometimes has a complicated functional form. We introduce the copula, a mathematical tool to construct an arbitrary multivariate…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-25 Masanori Sato , Kiyotomo Ichiki , Tsutomu T. Takeuchi

We present a comparison of simulation-based inference to full, field-based analytical inference in cosmological data analysis. To do so, we explore parameter inference for two cases where the information content is calculable analytically:…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-08 T. Lucas Makinen , Tom Charnock , Justin Alsing , Benjamin D. Wandelt

This work introduces a novel approach for generating conditional probabilistic rainfall forecasts with temporal and spatial dependence. A two-step procedure is employed. Firstly, marginal location-specific distributions are jointly…

Methodology · Statistics 2025-03-31 David Huk , Rilwan A. Adewoyin , Ritabrata Dutta

We study cosmic variance in deep high redshift surveys and its influence on the determination of the luminosity function for high redshift galaxies. For several survey geometries relevant for HST and JWST instruments, we characterize the…

Astrophysics · Physics 2020-07-28 M. Trenti , M. Stiavelli

We introduce a variational Bayesian neural network where the parameters are governed via a probability distribution on random matrices. Specifically, we employ a matrix variate Gaussian \cite{gupta1999matrix} parameter posterior…

Machine Learning · Statistics 2016-06-24 Christos Louizos , Max Welling

Normal variance mixtures are a class of multivariate distributions that generalize the multivariate normal by randomizing (or mixing) the covariance matrix via multiplication by a non-negative random variable W. The multivariate t…

Computation · Statistics 2020-06-16 Erik Hintz , Marius Hofert , Christiane Lemieux

In qualitative statistics, permutation tests are very popular, mainly because of their finite-sample exactness under exchangeability. However, in non-exchangeable settings, the covariance structure of permuted statistics typically differs…

Methodology · Statistics 2026-04-09 Merle Munko , Paavo Sattler

A methodology to perform topological regularization via information filtering network is introduced. This methodology can be directly applied to covariance selection problem providing an instrument for sparse probabilistic modeling with…

Machine Learning · Computer Science 2021-11-02 Tomaso Aste
‹ Prev 1 3 4 5 6 7 10 Next ›