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The estimation of small probabilities of failure from computer simulations is a classical problem in engineering, and the Subset Simulation algorithm proposed by Au & Beck (Prob. Eng. Mech., 2001) has become one of the most popular method…

Computation · Statistics 2012-07-10 Ling Li , Julien Bect , Emmanuel Vazquez

We expound in detail a method frequently used to reduce the Dirac equation in D-dimensional (D >= 4) spherically symmetric spacetimes to a pair of coupled partial differential equations in two variables. As a simple application of these…

General Relativity and Quantum Cosmology · Physics 2010-02-03 A. Lopez-Ortega

The Bayesian smoothing equations are generally intractable for systems described by nonlinear stochastic differential equations and discrete-time measurements. Gaussian approximations are a computationally efficient way to approximate the…

Dynamical Systems · Mathematics 2016-04-05 Juha Ala-Luhtala , Simo Särkkä , Robert Piché

A simple and efficient method for characterization of multidimensional Gaussian states is suggested and experimentally demonstrated. Our scheme shows analogies with tomography of finite dimensional quantum states, with the covariance matrix…

We adopt the frozen Gaussian approximation (FGA) for modeling seismic waves. The method belongs to the category of ray-based beam methods. It decomposes seismic wavefield into a set of Gaussian functions and propagates these Gaussian…

Geophysics · Physics 2013-04-15 Xu Yang , Jianfeng Lu , Sergey Fomel

Weighted Gaussian Curvature is an important measurement for images. However, its conventional computation scheme has low performance, low accuracy and requires that the input image must be second order differentiable. To tackle these three…

Computer Vision and Pattern Recognition · Computer Science 2021-01-21 Yuanhao Gong , Wenming Tang , Lebin Zhou , Lantao Yu , Guoping Qiu

In this paper, we give interior gradient and Hessian estimates for systems of semi-linear degenerate elliptic partial differential equations on bounded domains, using both tools of backward stochastic differential equations and…

Probability · Mathematics 2018-08-01 Jun Dai , Shanjian Tang , Bingjie Wu

Some years ago, one of the authors~(MM) revived a concept to which he gave the name of single-particle Dirac oscillator, while another~(CQ) showed that it corresponds to a realization of supersymmetric quantum mechanics. The Dirac…

High Energy Physics - Theory · Physics 2011-07-19 M. Moshinsky , C. Quesne , Yu. F. Smirnov

We present a recent work on the Dirac equation in a curved spacetime. In addition to the standard equation, two alternative versions are considered, derived from wave mechanics, and based on the tensor representation of the Dirac field. The…

General Relativity and Quantum Cosmology · Physics 2008-10-06 Mayeul Arminjon , Frank Reifler

We present a new technique, based on semivariogram methodology, for obtaining point estimates for use in prior modeling for solving Bayesian inverse problems. This method requires a connection between Gaussian processes with covariance…

Numerical Analysis · Mathematics 2020-05-12 Richard D. Brown , Johnathan M. Bardsley , Tiangang Cui

We present an approach for adapting the Gaussian dispersion analysis (GDA) of optical materials to time-domain simulations. Within a GDA model, the imaginary part of a measured dielectric function is presented as a sum of Gaussian…

Optics · Physics 2022-07-20 Ludmila Prokopeva , Samuel Peana , Alexander Kildishev

A Gaussian resolution method for the computation of equilibrium density matrices rho(T) for a general multidimensional quantum problem is presented. The variational principle applied to the ``imaginary time'' Schroedinger equation provides…

Quantum Physics · Physics 2009-11-10 P. Frantsuzov , A. Neumaier , V. A. Mandelshtam

Several machine learning problems arising in natural language processing can be modeled as a sequence labeling problem. We provide Gaussian process models based on pseudo-likelihood approximation to perform sequence labeling. Gaussian…

Machine Learning · Computer Science 2016-09-22 P. K. Srijith , P. Balamurugan , Shirish Shevade

Gaussian processes are a powerful framework for quantifying uncertainty and for sequential decision-making but are limited by the requirement of solving linear systems. In general, this has a cubic cost in dataset size and is sensitive to…

We study above-barrier scattering of Dirac electrons by a smooth electrostatic potential combined with a coordinate-dependent mass in graphene. We assume that the potential and mass are sufficiently smooth, so that we can define a small…

Mesoscale and Nanoscale Physics · Physics 2018-08-29 K. J. A. Reijnders , D. S. Minenkov , M. I. Katsnelson , S. Yu. Dobrokhotov

We review the Dirac formalism for dealing with constraints in a canonical Hamiltonian formulation and discuss gauge freedom and display constraints for gauge theories in a general context. We introduce the Dirac bracket and show that it…

Mathematical Physics · Physics 2020-07-21 Jon Allen , Richard A. Matzner

Gaussian process (GP) predictors are an important component of many Bayesian approaches to machine learning. However, even a straightforward implementation of Gaussian process regression (GPR) requires O(n^2) space and O(n^3) time for a…

Machine Learning · Statistics 2012-11-06 Krzysztof Chalupka , Christopher K. I. Williams , Iain Murray

We analyze the Gaussian approximation as a method to obtain the first and second moments of a stochastic process described by a master equation. We justify the use of this approximation with ideas coming from van Kampen's expansion approach…

Statistical Mechanics · Physics 2015-05-18 Luis F. Lafuerza , Raul Toral

We reconsider in details the Dirac equation in the context of the Magueijo-Smolin approach to the Doubly Special Relativity. Starting from the deformed dispersion relation we obtain the Dirac equation in momentum space, allowing us to…

High Energy Physics - Theory · Physics 2011-06-08 Z. Belhadi , F. Ménas , A. Bérard , P. Gosselin , H. Mohrbach

By employing a pseudo-orthonormal coordinate-free approach, the Dirac equation for particles in the Kerr--Newman spacetime is separated into its radial and angular parts. In the massless case to which a special attention is given, the…

High Energy Physics - Theory · Physics 2021-02-15 Ciprian Dariescu , Marina-Aura Dariescu , Cristian Stelea