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Neural ordinary differential equations (Neural ODEs) is a class of machine learning models that approximate the time derivative of hidden states using a neural network. They are powerful tools for modeling continuous-time dynamical systems,…

Machine Learning · Statistics 2024-07-16 Wenbo Hao

Reduced order modeling lowers the computational cost of solving PDEs by learning a low-order spatial representation from data and dynamically evolving these representations using manifold projections of the governing equations. While…

Fluid Dynamics · Physics 2024-07-10 Vedant Puri , Aviral Prakash , Levent Burak Kara , Yongjie Jessica Zhang

Machine learning has been successfully applied to various fields of scientific computing in recent years. In this work, we propose a sparse radial basis function neural network method to solve elliptic partial differential equations (PDEs)…

Numerical Analysis · Mathematics 2023-09-07 Zhiwen Wang , Minxin Chen , Jingrun Chen

A common problem in cosmology is to integrate the product of two or more spherical Bessel functions (sBFs) with different configuration-space arguments against the power spectrum or its square, weighted by powers of wavenumber. Naively…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-03 Zachary Slepian , Yin Li , Marcel Schmittfull , Zvonimir Vlah

This paper focuses on regularisation methods using models up to the third order to search for up to second-order critical points of a finite-sum minimisation problem. The variant presented belongs to the framework of [3]: it employs random…

Numerical Analysis · Mathematics 2021-04-05 Stefania Bellavia , Gianmarco Gurioli , Benedetta Morini , Philippe L. Toint

Electrical Impedance Tomography gives rise to the severely ill-posed Calder\'on problem of determining the electrical conductivity distribution in a bounded domain from knowledge of the associated Dirichlet-to-Neumann map for the governing…

Analysis of PDEs · Mathematics 2022-01-26 Kim Knudsen , Aksel K. Rasmussen

In this work we analyze the convergence properties of the Spectral Deferred Correction (SDC) method originally proposed by Dutt et al. [BIT, 40 (2000), pp. 241--266]. The framework for this high-order ordinary differential equation (ODE)…

Numerical Analysis · Mathematics 2019-07-24 Mathew F. Causley , David C. Seal

Radiative effects in semi-inclusive hadron leptoproduction of unpolarized particles are calculated within the leading order approximation. The contributions of the infrared-free sum of the effects of real and virtual photon emission as well…

High Energy Physics - Phenomenology · Physics 2024-04-30 Igor Akushevich , Alexander Ilyichev , Stanislav Srednyak

In this work, we investigate the use of deep neural networks (DNNs) as surrogates for solving the inverse acoustic scattering problem of recovering a sound-soft obstacle from phaseless far-field measurements. We approximate the forward maps…

Numerical Analysis · Mathematics 2025-09-08 Yuxin Fan , Jiho Hong , Bangti Jin

This work addresses models (e.g. potential models of directed orbital systems- the manganates) in which an effective reduction dimensionality occurs as a result of a new symmetry which is intermediate between that of global and local gauge…

Statistical Mechanics · Physics 2007-05-23 Zohar Nussinov

Understanding how laser light scatters from realistic mirror surfaces is crucial for the design, com- missioning and operation of precision interferometers, such as the current and next generation of gravitational-wave detectors. Numerical…

Optics · Physics 2016-01-20 Daniel Brown , Rory Smith , Andreas Freise

This paper addresses the optimization problem of minimizing non-convex continuous functions, which is relevant in the context of high-dimensional machine learning applications characterized by over-parametrization. We analyze a randomized…

Machine Learning · Computer Science 2025-02-28 Jim Zhao , Aurelien Lucchi , Nikita Doikov

Discontinuous Finite Element Methods (DFEM) have been widely used for solving $S_n$ radiation transport problems in participative and non-participative media. In the DFEM $S_n$ methodology, the transport equation is discretized into a set…

Computational Physics · Physics 2019-06-11 Mauricio Tano , Jean Ragusa

Zeroth-order methods have become important tools for solving problems where we have access only to function evaluations. However, the zeroth-order methods only using gradient approximations are $n$ times slower than classical first-order…

Optimization and Control · Mathematics 2022-02-10 Erik Berglund , Sarit Khirirat , Xiaoyu Wang

We develop a rapid and accurate contour method for the solution of time-fractional PDEs. The method inverts the Laplace transform via an optimised stable quadrature rule, suitable for infinite-dimensional operators, whose error decreases…

Numerical Analysis · Mathematics 2022-02-09 Matthew J. Colbrook , Lorna J. Ayton

In this paper we consider the problem of minimizing composite objective functions consisting of a convex differentiable loss function plus a non-smooth regularization term, such as $L_1$ norm or nuclear norm, under R\'enyi differential…

Machine Learning · Computer Science 2019-09-26 Chen Chen , Jaewoo Lee

We study gradient-based optimization methods obtained by directly discretizing a second-order ordinary differential equation (ODE) related to the continuous limit of Nesterov's accelerated gradient method. When the function is smooth…

Optimization and Control · Mathematics 2018-11-29 Jingzhao Zhang , Aryan Mokhtari , Suvrit Sra , Ali Jadbabaie

Our objective is to leverage a differentiable radiance field \eg NeRF to reconstruct detailed 3D surfaces in addition to producing the standard novel view renderings. There have been related methods that perform such tasks, usually by…

Computer Vision and Pattern Recognition · Computer Science 2024-06-17 Yida Wang , David Joseph Tan , Nassir Navab , Federico Tombari

We have investigated bound modes in finite linear chains of dielectric particles of various lengths, interparticle spacing and particle materials. Through a unique application of the multisphere Mie scattering formalism, we have developed…

Optics · Physics 2015-06-26 Gail S. Blaustein , Alexander L. Burin

While new light sources allow for unprecedented resolution in experiments with X-rays, a theoretical understanding of the scattering cross-section is lacking. In the particular case of strongly correlated electron systems, numerical…

Strongly Correlated Electrons · Physics 2023-05-29 Krissia Zawadzki , Alberto Nocera , Adrian E. Feiguin