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We study the inverse problem of locating point sources from far-field data under plane wave incidence. A direct computational method is developed based on multiple scattering theory, using a novel indicator function to avoid iterative…

Analysis of PDEs · Mathematics 2025-09-18 Nana Meng

We consider the inverse source problem in the parabolic equation, where the unknown source possesses the semi-discrete formulation. Theoretically, we prove that the flux data from any nonempty open subset of the boundary can uniquely…

Numerical Analysis · Mathematics 2022-11-23 Guang Lin , Zecheng Zhang , Zhidong Zhang

This paper explores the reconstruction of a space-dependent parameter in inverse diffusion problems, proposing a shape-optimization-based approach. We consider a Robin boundary condition, physically motivated in diffuse optical tomography…

Numerical Analysis · Mathematics 2026-01-27 Manabu Machida , Hirofumi Notsu , Julius Fergy Tiongson Rabago

We introduce a diffusion-based generative model to describe the distribution of galaxies in our Universe directly as a collection of points in 3-D space (coordinates) optionally with associated attributes (e.g., velocities and masses),…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-24 Carolina Cuesta-Lazaro , Siddharth Mishra-Sharma

This work proposes a method for the two-dimensional simulation of Brownian particles in a fluid with restrictions. The method is based on simple numerical rules between two matrices. One of the matrix represent the identification of all…

Statistical Mechanics · Physics 2012-04-24 Eric Plaza

In this paper, we consider the prediction of the helium concentrations as function of a spatially variable source term perturbed by fractional Brownian motion. For the direct problem, we show that it is well-posed and has a unique mild…

Numerical Analysis · Mathematics 2022-06-07 Jing Li , Hao Cheng , Xiaoxiao Geng

This paper presents a new method, Diffusing Winding Gradients (DWG), for reconstructing watertight 3D surfaces from unoriented point clouds. Our method exploits the alignment between the gradients of the generalized winding number (GWN)…

Graphics · Computer Science 2024-10-10 Weizhou Liu , Jiaze Li , Xuhui Chen , Fei Hou , Shiqing Xin , Xingce Wang , Zhongke Wu , Chen Qian , Ying He

This paper is concerned with the numerical simulation of three dimensional time-dependent inverse source problems of acoustic waves. The reconstructions of both multiple stationary point sources and a moving point source are considered. The…

Numerical Analysis · Mathematics 2020-08-26 Bo Chen , Yukun Guo , Fuming Ma , Yao Sun

We consider the problem of reconstructing one-dimensional point sources from their Fourier measurements in a bounded interval $[-\Omega, \Omega]$. This problem is known to be challenging in the regime where the spacing of the sources is…

Signal Processing · Electrical Eng. & Systems 2024-06-11 Zetao Fei , Hai Zhang

This paper is concerned with the mathematical analysis of the inverse random source problem for the time fractional diffusion equation, where the source is assumed to be driven by a fractional Brownian motion. Given the random source, the…

Analysis of PDEs · Mathematics 2020-04-22 Xiaoli Feng , Peijun Li , Xu Wang

Fastest arrival events, where the first among many diffusing particles reaches a target, are central in triggering signal initiation in molecular stochastic systems. Classical approaches to simulate such events rely on full trajectory…

Probability · Mathematics 2026-05-26 Emmanuel Akame Mfoumou , David Holcman

We recover the Riemannian gradient of a given function defined on interior points of a Riemannian submanifold in the Euclidean space based on a sample of function evaluations at points in the submanifold. This approach is based on the…

Machine Learning · Computer Science 2023-06-06 Alvaro Almeida Gomez , Antônio J. Silva Neto , Jorge P. Zubelli

We consider an inverse elastic scattering problem of simultaneously reconstructing a rigid obstacle and the excitation sources using near-field measurements. A two-phase numerical method is proposed to achieve the co-inversion of multiple…

Numerical Analysis · Mathematics 2023-07-19 Yan Chang , Yukun Guo , Hongyu Liu , Deyue Zhang

In this paper, we present a novel shape reconstruction method leveraging diffusion model to generate 3D sparse point cloud for the object captured in a single RGB image. Recent methods typically leverage global embedding or local…

Computer Vision and Pattern Recognition · Computer Science 2023-08-16 Yan Di , Chenyangguang Zhang , Pengyuan Wang , Guangyao Zhai , Ruida Zhang , Fabian Manhardt , Benjamin Busam , Xiangyang Ji , Federico Tombari

A new method is proposed to numerically extract the diffusivity of a (typically nonlinear) diffusion equation from underlying stochastic particle systems. The proposed strategy requires the system to be in local equilibrium and have…

Statistical Mechanics · Physics 2018-05-09 Peter Embacher , Nicolas Dirr , Johannes Zimmer , Celia Reina

In the context of PDE-constrained optimization theory, source identification problems traditionally entail particles emerging from an unknown source distribution inside a domain, moving according to a prescribed stochastic process,…

Optimization and Control · Mathematics 2025-08-22 Richard B. Lehoucq , Scott A. McKinley , Petr Plecháč

In astrophysics a common goal is to infer the flux distribution of populations of scientifically interesting objects such as pulsars or supernovae. In practice, inference for the flux distribution is often conducted using the cumulative…

Applications · Statistics 2015-03-03 Raymond K. W. Wong , Paul Baines , Alexander Aue , Thomas C. M. Lee , Vinay L. Kashyap

We consider an inverse source problem in the stationary radiative transport through an absorbing and scattering medium in two dimensions. Using the angularly resolved radiation measured on an arc of the boundary, we propose a numerical…

Numerical Analysis · Mathematics 2023-06-08 Hiroshi Fujiwara , Kamran Sadiq , Alexandru Tamasan

In this paper, we consider the 1D wave equation where the spatial domain is a bounded interval. Assuming the initial conditions to be known, we are here interested in identifying an unknown source term, while we take the Neumann derivative…

Optimization and Control · Mathematics 2011-06-30 Marianne Chapouly , Mazyar Mirrahimi

We prove the existence of solutions to a non-linear, non-local, degenerate equation which was previously derived as the formal hydrodynamic limit of an active Brownian particle system, where the particles are endowed with a position and an…

Analysis of PDEs · Mathematics 2023-10-02 Martin Burger , Simon Schulz