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Copulas are now frequently used to construct or estimate multivariate distributions because of their ability to take into account the multivariate dependence of the different variables while separately specifying marginal distributions.…

Methodology · Statistics 2023-02-02 Mohamad A. Khaled , Robert Kohn

We propose reinterpreting copula density estimation as a discriminative task. Under this novel estimation scheme, we train a classifier to distinguish samples from the joint density from those of the product of independent marginals,…

Methodology · Statistics 2025-03-20 David Huk , Mark Steel , Ritabrata Dutta

We developed a modification to the calculation of the two-point correlation function commonly used in the analysis of large scale structure in cosmology. An estimator of the two-point correlation function is constructed by contrasting the…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-20 Regina Demina , Sanha Cheong , Segev BenZvi , Otto Hindrichs

We describe a Bayesian approach to estimating luminosity functions. We derive the likelihood function and posterior probability distribution for the luminosity function, given the observed data, and we compare the Bayesian approach with…

Astrophysics · Physics 2009-11-13 Brandon C. Kelly , Xiaohui Fan , Marianne Vestergaard

We tackle the problem of multi-task learning with copula process. Multivariable prediction in spatial and spatial-temporal processes such as natural resource estimation and pollution monitoring have been typically addressed using techniques…

Machine Learning · Computer Science 2014-06-03 Markus Schneider , Fabio Ramos

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…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-11 Chien-Hao Lin , Joachim Harnois-Déraps , Tim Eifler , Taylor Pospisil , Rachel Mandelbaum , Ann B. Lee , Sukhdeep Singh

Copulas are functions that describe dependence structures of random vectors, without describing their univariate marginals. In statistics, the separation is sometimes useful, the quality and/or quantity of available information on these two…

Computation · Statistics 2024-11-14 Oskar Laverny , Santiago Jimenez

Naive estimates of the statistics of large scale structure and weak lensing power spectrum measurements that include only Gaussian errors exaggerate their scientific impact. Non-linear evolution and finite volume effects are both…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-24 Emmanuel Schaan , Masahiro Takada , David N. Spergel

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

Recent methods for estimating sparse undirected graphs for real-valued data in high dimensional problems rely heavily on the assumption of normality. We show how to use a semiparametric Gaussian copula--or "nonparanormal"--for high…

Machine Learning · Statistics 2009-03-05 Han Liu , John Lafferty , Larry Wasserman

Context: Two-point correlation functions are used throughout cosmology as a measure for the statistics of random fields. When used in Bayesian parameter estimation, their likelihood function is usually replaced by a Gaussian approximation.…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-07 David Keitel , Peter Schneider

We define a copula process which describes the dependencies between arbitrarily many random variables independently of their marginal distributions. As an example, we develop a stochastic volatility model, Gaussian Copula Process Volatility…

Methodology · Statistics 2010-06-24 Andrew Gordon Wilson , Zoubin Ghahramani

We propose a new semi-parametric distributional regression smoother that is based on a copula decomposition of the joint distribution of the vector of response values. The copula is high-dimensional and constructed by inversion of a pseudo…

Methodology · Statistics 2020-06-30 Michael Stanley Smith , Nadja Klein

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…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-26 Robert Reischke , Alina Kiessling , Björn Malte Schäfer

A grand challenge of the 21st century cosmology is to accurately estimate the cosmological parameters of our Universe. A major approach to estimating the cosmological parameters is to use the large-scale matter distribution of the Universe.…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Siamak Ravanbakhsh , Junier Oliva , Sebastien Fromenteau , Layne C. Price , Shirley Ho , Jeff Schneider , Barnabas Poczos

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…

Astrophysics · Physics 2015-05-13 Tim Eifler , Peter Schneider , Jan Hartlap

The Gaussian copula is a powerful tool that has been widely used to model spatial and/or temporal correlated data with arbitrary marginal distributions. However, this kind of model can potentially be too restrictive since it expresses a…

Methodology · Statistics 2023-05-30 Moreno Bevilacqua , Eloy Alvarado , Christian Caamaño-Carrillo

This paper deals with a situation when one is interested in the dependence structure of a multidimensional response variable in the presence of a multivariate covariate. It is assumed that the covariate affects only the marginal…

Statistics Theory · Mathematics 2019-03-12 Marek Omelka , Šárka Hudecová , Natalie Neumeyer

We exploit Gaussian copulas to specify a class of multivariate circular distributions and obtain parametric models for the analysis of correlated circular data. This approach provides a straightforward extension of traditional multivariate…

Methodology · Statistics 2024-06-07 Francesco Lagona , Marco Mingione

We propose notions of calibration for probabilistic forecasts of general multivariate quantities. Probabilistic copula calibration is a natural analogue of probabilistic calibration in the univariate setting. It can be assessed empirically…

Methodology · Statistics 2013-07-30 Johanna F. Ziegel , Tilmann Gneiting