English
Related papers

Related papers: Refractor surfaces determined by near-field data

200 papers

There is widespread interest in estimating the fluorescence properties of natural materials in an image. However, the separation between reflected and fluoresced components is difficult, because it is impossible to distinguish reflected and…

Computer Vision and Pattern Recognition · Computer Science 2016-05-16 Henryk Blasinski , Joyce Farrell , Brian Wandell

The theory of specular X-ray reflectivity from a rough interface based upon the reflection function method (RFM) is proposed. The RFM transforms the second order differential equation for the wave amplitude into the non-linear first order…

Materials Science · Physics 2007-05-23 N. V. Bagrets , E. A. Kravtsov , V. V. Ustinov

For a class of quasilinear parabolic systems with nonlinear Robin boundary conditions we construct a compact local solution semiflow in a nonlinear phase space of high regularity. We further show that a priori estimates in lower norms are…

Analysis of PDEs · Mathematics 2012-02-20 Martin Meyries

Recently, differentiable volume rendering in neural radiance fields (NeRF) has gained a lot of popularity, and its variants have attained many impressive results. However, existing methods usually assume the scene is a homogeneous volume so…

Computer Vision and Pattern Recognition · Computer Science 2022-11-29 Jen-I Pan , Jheng-Wei Su , Kai-Wen Hsiao , Ting-Yu Yen , Hung-Kuo Chu

Consider time-harmonic acoustic scattering from a bounded penetrable obstacle $D\subset \mathbb R^N$ embedded in a homogeneous background medium. The index of refraction characterizing the material inside $D$ is supposed to be H\"older…

Analysis of PDEs · Mathematics 2015-07-29 Guanghui Hu , Mikko Salo , Esa V. Vesalainen

We consider inverse obstacle and transmission scattering problems where the source of the incident waves is located on a smooth closed surface that is a boundary of a domain located outside of the obstacle/inhomogeneity of the media. The…

Mathematical Physics · Physics 2017-10-12 Evgeny Lakshtanov , Boris Vainberg

We obtain a nonperturbative, analytical solution to integral equation of scattering theory by assuming the field within the scattering object is a spherical wave with a scattering amplitude equal to that of the far field. This approximation…

Classical Physics · Physics 2018-09-26 Brian Slovick , Srini Krishnamurthy

We study light propagation and gravitational lensing in scalar-tensor theories of gravity by using a static, axisymmetric exterior solution. The solution has asymptotic flatness properties and is reduced to Voorhees's one in the case of a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Shin-ei Tsuneishi , Kazuya Watanabe , Tooru Tsuchida

The reconstruction of a 3D object or a scene is a classical inverse problem in Computer Vision. In the case of a single image this is called the Shape-from-Shading (SfS) problem and it is known to be ill-posed even in a simplified version…

Numerical Analysis · Mathematics 2016-01-28 Silvia Tozza , Maurizio Falcone

We introduce novel a posteriori error indicators for a nonlinear least-squares solver for smooth solutions of the Monge--Amp\`ere equation on convex polygonal domains in $\mathbb{R}^2$. At each iteration, our iterative scheme decouples the…

Numerical Analysis · Mathematics 2025-09-09 Alexandre Caboussat , Anna Peruso , Marco Picasso

The present article proposes a partial answer to the explicit inversion of the tensor tomography problem in two dimensions, by proving injectivity over certain kinds of tensors and providing reconstruction formulas for them. These tensors…

Analysis of PDEs · Mathematics 2015-06-18 François Monard

We consider a smooth one-parameter family $t \to f_t$ of diffeomorphisms with compact transitive Axiom A attractors. Our first result (corrected) is that for any function $G$ in the Sobolev space $H^r_p$, with $p>1$ and $0<r<1/p$, the map…

Dynamical Systems · Mathematics 2017-06-22 Viviane Baladi , Tobias Kuna , Valerio Lucarini

High-resolution field localization in three dimensions is one of the main challenges in optics and has immense importance in fields such as chemistry, biology, and medicine. In order to generate the time reversed signal of a monochromatic…

Optics · Physics 2020-07-01 Asaf Farhi

In this paper we introduce a new fix point iteration scheme for solving nonlinear electromagnetic scattering problems. The method is based on a spectral formulation of Maxwell's equations called the Bidirectional Pulse Propagation…

Classical Physics · Physics 2026-03-27 Per Kristen Jakobsen

We revisit the electromagnetic problem of wave incidence upon a uniform, dissipative dielectric slab of finite thickness. While this problem is easily solved via interface field continuity, we treat it under the viewpoint of radiative…

Classical Physics · Physics 2018-07-17 J. A. Grzesik

The resolvent Krylov subspace method builds approximations to operator functions $f(A)$ times a vector $v$. For the semigroup and related operator functions, this method is proved to possess the favorable property that the convergence is…

Numerical Analysis · Mathematics 2019-07-15 Volker Grimm , Tanja Göckler

This paper is concerned with inverse scattering problems of determining the support of an isotropic and homogeneous penetrable body from knowledge of multi-static far-field patterns in acoustics and in linear elasticity. The normal…

Analysis of PDEs · Mathematics 2024-04-11 Chun Liu , Guanghui Hu , Jianli Xiang , Jiayi Zhang

We consider a family of steady free-surface flow problems in two dimensions, concentrating on the effect of nonlinearity on the train of gravity waves that appear downstream of a disturbance. By exploiting standard complex variable…

Fluid Dynamics · Physics 2018-03-14 Ravindra Pethiyagoda , Timothy J. Moroney , Scott W. McCue

We propose to tackle the multiview photometric stereo problem using an extension of Neural Radiance Fields (NeRFs), conditioned on light source direction. The geometric part of our neural representation predicts surface normal direction,…

Computer Vision and Pattern Recognition · Computer Science 2022-07-15 Meghna Asthana , William A. P. Smith , Patrik Huber

We classify the surfaces translating under the flows by sub-affine-critical powers of the Gauss curvature. This, in particular, lists all translating solitons possibly model Type II singularities for convex closed solutions in all positive…

Differential Geometry · Mathematics 2024-07-22 Beomjun Choi , Kyeongsu Choi , Soojung Kim