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Related papers: Copula Cosmology: Constructing a Likelihood Functi…

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In this paper we describe a theory of a cumulative distribution function on a space with an order from a probability measure defined in this space. This distribution function plays a similar role to that played in the classical case.…

Probability · Mathematics 2019-04-12 J. F. Gálvez-Rodríguez , M. A. Sánchez-Granero

Copulas are mathematical objects that fully capture the dependence structure among random variables and hence, offer a great flexibility in building multivariate stochastic models. In statistics, a copula is used as a general way of…

Methodology · Statistics 2013-10-01 Abhik Ghosh , Aritra Chakravorty

The ability to obtain reliable point estimates of model parameters is of crucial importance in many fields of physics. This is often a difficult task given that the observed data can have a very high number of dimensions. In order to…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Janis Fluri , Aurelien Lucchi , Tomasz Kacprzak , Alexandre Refregier , Thomas Hofmann

In this paper, we analyze the relative errors in various reliability measures due to the tacit assumption that the components associated with a $n$-component series system or a parallel system are independently working where the components…

Statistics Theory · Mathematics 2025-03-28 Subarna Bhattacharjee , Aninda Kumar Nanda , Subhashree Patra

Gaussian processes provide a method for extracting cosmological information from observations without assuming a cosmological model. We carry out cosmography -- mapping the time evolution of the cosmic expansion -- in a model-independent…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-11 Arman Shafieloo , Alex G. Kim , Eric V. Linder

The estimation of dependencies between multiple variables is a central problem in the analysis of financial time series. A common approach is to express these dependencies in terms of a copula function. Typically the copula function is…

Machine Learning · Statistics 2013-07-02 José Miguel Hernández-Lobato , James Robert Lloyd , Daniel Hernández-Lobato

For a given statistic, A, the cosmic distribution function, Upsilon(VA), is the probability of measuring a value VA in a finite galaxy catalog. For statistics related to count-in-cells, such as factorial moments, F_k, the average…

Astrophysics · Physics 2007-05-23 S. Colombi , I. Szapudi , the VIRGO consortium

We propose, for multivariate Gaussian copula models with unknown margins and structured correlation matrices, a rank-based, semiparametrically efficient estimator for the Euclidean copula parameter. This estimator is defined as a one-step…

Methodology · Statistics 2014-10-02 Johan Segers , Ramon van den Akker , Bas J. M. Werker

We discuss the problem of constraining cosmological parameters with cosmic microwave background band--power estimates. Because these latter are variances, they do not have gaussian distribution functions and, hence, the standard…

Astrophysics · Physics 2007-05-23 J. G. Bartlett , A. Blanchard , M. Douspis , M. Le Dour

For known gravitational lens systems the redshift distribution of the lenses is compared with theoretical expectations for $10^{4}$~Friedmann-Lema\^\i tre~cosmological models, which more than cover the range of possible cases. The…

Astrophysics · Physics 2011-05-23 Phillip Helbig , Rainer Kayser

This paper addresses the problem of quantification and propagation of uncertainties associated with dependence modeling when data for characterizing probability models are limited. Practically, the system inputs are often assumed to be…

Computation · Statistics 2020-04-14 Jiaxin Zhang , Michael D. Shields

A model-independent or non-parametric approach for modeling a database has been widely used in cosmology. In these scenarios, the data has been used directly to reconstruct an underlying function. In this work, we introduce a novel…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-19 Ahmad Mehrabi

Joint modelling of longitudinal and time-to-event data is usually described by a joint model which uses shared or correlated latent effects to capture associations between the two processes. Under this framework, the joint distribution of…

Methodology · Statistics 2022-03-07 Zili Zhang , Christiana Charalambous , Peter Foster

The likelihood function plays a pivotal role in statistical inference; it is adaptable to a wide range of models and the resultant estimators are known to have good properties. However, these results hinge on correct specification of the…

Statistics Theory · Mathematics 2017-12-15 Adam Jaeger , Nicole Lazar

Predicting the dependencies between observations from multiple time series is critical for applications such as anomaly detection, financial risk management, causal analysis, or demand forecasting. However, the computational and numerical…

Machine Learning · Computer Science 2019-10-28 David Salinas , Michael Bohlke-Schneider , Laurent Callot , Roberto Medico , Jan Gasthaus

Factor models are a parsimonious way to explain the dependence of variables using several latent variables. In Gaussian 1-factor and structural factor models (such as bi-factor, oblique factor) and their factor copula counterparts, factor…

Methodology · Statistics 2022-05-31 Xinyao Fan , Harry Joe

Probability density estimation from observed data constitutes a central task in statistics. In this brief, we focus on the problem of estimating the copula density associated to any observed data, as it fully describes the dependence…

Machine Learning · Computer Science 2025-07-09 Nunzio A. Letizia , Nicola Novello , Andrea M. Tonello

A new class of copulas based on order statistics was introduced by Baker (2008). Here, further properties of the bivariate and multivariate copulas are described, such as that of likelihood ratio dominance (LRD), and further bivariate…

Methodology · Statistics 2014-12-03 Rose Baker

The omnipotence of copulas when modeling dependence given marg\-inal distributions in a multivariate stochastic situation is assured by the Sklar's theorem. Montes et al.\ (2015) suggest the notion of what they call an \emph{imprecise…

Probability · Mathematics 2022-09-29 Matjaž Omladič , Damjan Škulj

Use of copula for the purpose of modeling dependence has been receiving considerable attention in recent times. On the other hand, search for multivariate copulas with desirable dependence properties also is an important area of research.…

Methodology · Statistics 2025-02-18 Subhajit Chattopadhyay