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Related papers: On the broken ray transform

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We show injectivity of the X-ray transform and the $d$-plane Radon transform for distributions on the $n$-torus, lowering the regularity assumption in the recent work by Abouelaz and Rouvi\`ere. We also show solenoidal injectivity of the…

Differential Geometry · Mathematics 2016-06-21 Joonas Ilmavirta

A new method for investigation of x-ray propagation in a rough narrow dielectric waveguide is proposed on the basis of the numerical integration of the quazioptical equation. In calculations a model rough surface was used with the given…

Optics · Physics 2007-05-23 T. A. Bobrova , L. I. Ognev

This work gives an expository account of certain applications of microlocal analysis in three geometric inverse problems. We will discuss the geodesic X-ray transform inverse problem, the Gelfand problem for the wave equation on a…

Analysis of PDEs · Mathematics 2023-12-14 Mikko Salo

Conformal transformation optics provides a simple scheme for manipulating light rays with inhomogeneous isotropic dielectrics. However, there is usually discontinuity for refractive index profile at branch cuts of different virtual Riemann…

Optics · Physics 2018-02-08 Lin Xu , Tomáš Tyc , Huanyang Chen

We study numerical methods of tomography in domains with a reflecting obstacle. It will be shown that tomography with sets containing both broken rays, i.e. rays reflecting at the obstacle, as well as unbroken rays, has a smaller error…

Numerical Analysis · Mathematics 2012-02-14 Kamen Lozev

Scanning transmission X-ray microscopy and ptychography have become mature tools for high-resolution, element-specific imaging of nanoscale structures. However, transmission geometries impose stringent constraints on sample thickness and…

In this article we introduce an approach for studying the geodesic X-ray transform and related geometric inverse problems by using Carleman estimates. The main result states that on compact negatively curved manifolds (resp. nonpositively…

Analysis of PDEs · Mathematics 2021-11-29 Gabriel P. Paternain , Mikko Salo

We prove two injectivity theorems for the geodesic ray transform on two-dimensional, complete, simply connected Riemannian manifolds with non-positive Gaussian curvature, also known as Cartan-Hadamard manifolds. The first theorem is…

Differential Geometry · Mathematics 2016-12-15 Jere Lehtonen

Generalized Abel equations have been employed in the recent literature to invert Radon transforms which arise in a number of important imaging applications, including Compton Scatter Tomography (CST), Ultrasound Reflection Tomography (URT),…

Functional Analysis · Mathematics 2023-06-16 James W. Webber

In a transformation method, the numerical solution of a given boundary value problem is obtained by solving one or more related initial value problems. Therefore, a transformation method, like a shooting method, is an initial value method.…

Numerical Analysis · Mathematics 2020-03-19 Riccardo Fazio

We study the geodesic X-ray transform $X$ on compact Riemannian surfaces with conjugate points. Regardless of the type of the conjugate points, we show that we cannot recover the singularities and therefore, this transform is always…

Differential Geometry · Mathematics 2015-05-20 François Monard , Plamen Stefanov , Gunther Uhlmann

The monograph contains a systematic treatment of a circle of problems in analysis and integral geometry related to inversion of the Radon transform on the space of real rectangular matrices. This transform assigns to a function $f$ on the…

Functional Analysis · Mathematics 2007-05-23 E. Ournycheva , B. Rubin

This work continues the development of the raytracing method of [1] for computing the scattered fields from metasurfaces characterized by locally periodic reflection and transmission coefficients. In this work, instead of describing the…

Optics · Physics 2022-02-16 Scott Stewart , Yvo L. C. de Jong , Tom J. Smy , Shulabh Gupta

We present a novel method of simulating wave effects in graphics using ray--based renderers with a new function: the Wave BSDF (Bidirectional Scattering Distribution Function). Reflections from neighboring surface patches represented by…

Graphics · Computer Science 2011-01-31 Tom Cuypers , Se Baek Oh , Tom Haber , Philippe Bekaert , Ramesh Raskar

Multiple scattering of polarised electromagnetic waves in diffusive media is investigated by means of radiative transfer theory. The method becomes exact in several situations of interest, such as a thick-slab experiment (slab thickness L…

Condensed Matter · Physics 2009-10-28 E. Amic , J. M. Luck , Th. M. Nieuwenhuizen

A solution to the inversion problem of scattering would offer aberration-free diffraction-limited 3D images without the resolution and depth-of-field limitations of lens-based tomographic systems. Powerful algorithms are increasingly being…

Reflected diffusions in convex polyhedral domains arise in a variety of applications, including interacting particle systems, queueing networks, biochemical reaction networks and mathematical finance. Under suitable conditions on the data,…

Probability · Mathematics 2017-05-08 David Lipshutz , Kavita Ramanan

Radiative transfer (RT) problems in which the source function includes a scattering-like integral are typical two-points boundary problems. Their solution via differential equations implies to make hypotheses on the solution itself, namely…

Solar and Stellar Astrophysics · Physics 2015-05-30 E. Simonneau , O. Cardona , L. Crivellari

Reconfigurable reflectors have a significant potential in future telecommunication systems, and approaches to the design and realization of full and tunable reflection control are now actively studied. Reflectarrays, being the classical…

Applied Physics · Physics 2023-06-28 Fu Liu , Do-Hoon Kwon , Sergei A. Tretyakov

Realizing continuous sweeping of perfect anomalous reflection in a wide angular range has become a technical challenge. This challenge cannot be overcome by the conventional aperiodic reflectarrays and periodic metasurfaces or metagratings.…