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We present a global analysis program for the generalized parton distributions (GPDs) based on conformal moment expansion. We apply the strategy of universal moment parameterization to fit both the collinear parton distribution functions…

High Energy Physics - Phenomenology · Physics 2022-10-19 Yuxun Guo , Xiangdong Ji , Kyle Shiells

We present an investigation of the theoretical uncertainties in parton distribution functions (PDFs) due to missing higher-order corrections in the perturbative predictions used in the fit, and their relationship to the uncertainties in…

High Energy Physics - Phenomenology · Physics 2019-05-02 L. A. Harland-Lang , R. S. Thorne

Gaussian mixture models (GMMs) are ubiquitous in statistical learning, particularly for unsupervised problems. While full GMMs suffer from the overparameterization of their covariance matrices in high-dimensional spaces, spherical GMMs…

Machine Learning · Statistics 2025-11-10 Tom Szwagier , Pierre-Alexandre Mattei , Charles Bouveyron , Xavier Pennec

We present an analysis of parton distribution functions (PDFs) of the proton using Markov Chain Monte Carlo (MCMC) methods. The MCMC approach naturally implements Bayes' theorem and thus provides a means to directly sample the underlying…

High Energy Physics - Phenomenology · Physics 2026-03-31 Peter Risse , Nasim Derakhshanian , Tomas Jezo , Karol Kovarik , Aleksander Kusina

We present the MCscales approach for incorporating scale uncertainties in parton distribution functions (PDFs). The new methodology builds on the Monte Carlo sampling for propagating experimental uncertainties into the PDF space that…

High Energy Physics - Phenomenology · Physics 2023-03-27 Zahari Kassabov , Maria Ubiali , Cameron Voisey

We present a new public code, FPPDF, to perform global fits of parton distribution functions (PDFs). The fitting methodology follows that implemented by the MSHT collaboration, namely applying a fixed polynomial parameterisation of the PDFs…

High Energy Physics - Phenomenology · Physics 2026-02-10 J. M. Cruz-Martinez , T. Giani , L. A. Harland-Lang

We examine the dependence of parton distribution functions (PDFs) on the value of the QCD coupling strength $\alpha_{s}(M_{Z})$. We explain a simple method that is rigorously valid in the quadratic approximation normally applied in PDF…

High Energy Physics - Phenomenology · Physics 2014-11-20 Hung-Liang Lai , Joey Huston , Zhao Li , Pavel Nadolsky , Jon Pumplin , Daniel Stump , C. -P. Yuan

We present a new regression model for the determination of parton distribution functions (PDF) using techniques inspired from deep learning projects. In the context of the NNPDF methodology, we implement a new efficient computing framework…

High Energy Physics - Phenomenology · Physics 2019-09-04 Stefano Carrazza , Juan Cruz-Martinez

Reasoning about the pose, i.e. position and orientation of objects is one of the cornerstones of robotic manipulation under uncertainty. In a number of joint research projects our group is developing a robotic perception system that…

Robotics · Computer Science 2017-07-10 Wendelin Feiten , Muriel Lang

We present a new subspace-based method to construct probabilistic models for high-dimensional data and highlight its use in anomaly detection. The approach is based on a statistical estimation of probability density using densities of…

Machine Learning · Computer Science 2021-08-16 Cetin Savkli , Catherine Schwartz

The current scientific standard in PDF uncertainty estimation relies either on repeated fits over artificially generated data to arrive at Monte Carlo samples of best fits or on the Hessian method, which uses a quadratic expansion of the…

High Energy Physics - Phenomenology · Physics 2024-07-23 Peter Risse , Nasim Derakhshanian , Tomas Ježo , Karol Kovařík , Aleksander Kusina

Global data association is an essential prerequisite for robot operation in environments seen at different times or by different robots. Repetitive or symmetric data creates significant challenges for existing methods, which typically rely…

Robotics · Computer Science 2025-09-22 Yixuan Jia , Mason B. Peterson , Qingyuan Li , Yulun Tian , Jonathan P. How

This work examines the problem of using finite Gaussian mixtures (GM) probability density functions in recursive Bayesian peer-to-peer decentralized data fusion (DDF). It is shown that algorithms for both exact and approximate GM DDF lead…

Signal Processing · Electrical Eng. & Systems 2019-07-10 Nisar R. Ahmed

Deterministic mathematical models, such as those specified via differential equations, are a powerful tool to communicate scientific insight. However, such models are necessarily simplified descriptions of the real world. Generalised…

Methodology · Statistics 2025-03-24 Zheyang Shen , Jeremias Knoblauch , Sam Power , Chris. J. Oates

Context. Whenever correlation functions are used for inference about cosmological parameters in the context of a Bayesian analysis, the likelihood function of correlation functions needs to be known. Usually, it is approximated as a…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-06 Philipp Wilking , Peter Schneider

We develop a general method to quantify the uncertainties of parton distribution functions and their physical predictions, with emphasis on incorporating all relevant experimental constraints. The method uses the Hessian formalism to study…

High Energy Physics - Phenomenology · Physics 2008-12-18 J. Pumplin , D. Stump , R. Brock , D. Casey , J. Huston , J. Kalk , H. L. Lai , W. K. Tung

Gaussian Mixture Models are a powerful tool in Data Science and Statistics that are mainly used for clustering and density approximation. The task of estimating the model parameters is in practice often solved by the Expectation…

Machine Learning · Statistics 2022-08-25 Lena Sembach , Jan Pablo Burgard , Volker H. Schulz

Since Pearson [Philosophical Transactions of the Royal Society of London. A, 185 (1894), pp. 71-110] first applied the method of moments (MM) for modeling data as a mixture of one-dimensional Gaussians, moment-based estimation methods have…

Machine Learning · Computer Science 2025-07-29 Liu Zhang , Oscar Mickelin , Sheng Xu , Amit Singer

Contextual optimization enhances decision quality by leveraging side information to improve predictions of uncertain parameters. However, existing approaches face significant challenges when dealing with multimodal or mixtures of…

Optimization and Control · Mathematics 2025-09-19 YoungChul Yoon , Grani A. Hanasusanto , Yijie Wang

We formulate a general approach to the inclusion of theoretical uncertainties, specifically those related to the missing higher order uncertainty (MHOU), in the determination of parton distribution functions (PDFs). We demonstrate how,…