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In this article we propose a numerical algorithm to compute the intensity and polarization of a polychromatic electromagnetic radiation crossing a medium with graded refractive index and modeled by the Vector Radiative Refractive Transfer…

Analysis of PDEs · Mathematics 2024-08-06 Olivier Pironneau

We consider the imaging problem of the reconstruction of a three-dimensional object via optical diffraction tomography under the assumptions of the Born approximation. Our focus lies in the situation that a rigid object performs an…

Numerical Analysis · Mathematics 2024-07-11 Robert Beinert , Michael Quellmalz

There is a commutative algebra of differential-difference operators, with two parameters, associated to any dihedral group with an even number of reflections. The intertwining operator relates this algebra to the algebra of partial…

Classical Analysis and ODEs · Mathematics 2008-04-24 Charles F. Dunkl

Motivated by a use case in theoretical hadron physics, we revisit an application of a pole-sum fit to dressing functions of a confined quark propagator. More precisely, we investigate approaches to determine the number and positions of the…

High Energy Physics - Phenomenology · Physics 2023-11-09 S. Kaidisch , T. U. Hilger , A. Krassnigg , W. Lucha

This paper presents a fast high-order method for the solution of two-dimensional problems of scattering by penetrable inhomogeneous media, with application to high-frequency configurations containing (possibly) discontinuous refractivities.…

Numerical Analysis · Mathematics 2023-07-31 Oscar P. Bruno , Ambuj Pandey

In analogy with steerable wavelets, we present a general construction of adaptable tight wavelet frames, with an emphasis on scaling operations. In particular, the derived wavelets can be "dilated" by a procedure comparable to the operation…

Computer Vision and Pattern Recognition · Computer Science 2017-06-20 Zsuzsanna Püspöki , John Paul Ward , Daniel Sage , Michael Unser

In this paper, a novel formula expressing explicitly the fractional-order derivatives, in the sense of Riesz-Feller operator, of Jacobi polynomials is presented. Jacobi spectral collocation method together with trapezoidal rule are used to…

Numerical Analysis · Mathematics 2018-03-30 N. H. Sweilam , M. M. Abou Hasan

We analyze and develop numerical methods for time-harmonic wave scattering in metallic waveguide structures of infinite extent. We show that radiation boundary conditions formulated via projectors onto outgoing modes determine the…

Numerical Analysis · Mathematics 2025-09-26 Tristan Goodwill , Shidong Jiang , Manas Rachh , Kosuke Sugita

In this lecture, we describe a number of advanced gain calibration techniques. In particular, self-calibration is an important tool in interferometric imaging at all wavelengths. It allows the observer to determine and remove residual phase…

Instrumentation and Methods for Astrophysics · Physics 2018-05-15 Crystal L. Brogan , Todd R. Hunter , Ed B. Fomalont

Analytic interpolation problems with rationality and derivative constraints occur in many applications in systems and control. In this paper we present a new method for the multivariable case, which generalizes our previous results on the…

Optimization and Control · Mathematics 2019-03-14 Yufang Cui , Anders Lindquist

In this paper, the WKB approximation to the scattering problem is developed without the divergences which usually appear at the classical turning points. A detailed procedure of complexification is shown to generate results identical to the…

Quantum Physics · Physics 2009-10-30 D. Cocolicchio , M. Viggiano

Automatic differentiation is everywhere, but there exists only minimal documentation of how it works in complex arithmetic beyond stating "derivatives in $\mathbb{C}^d$" $\cong$ "derivatives in $\mathbb{R}^{2d}$" and, at best, shallow…

Mathematical Software · Computer Science 2024-12-11 Nicholas Krämer

We introduce a novel technique for constructing higher-order variational integrators for Hamiltonian systems of ODEs. In particular, we are concerned with generating globally smooth approximations to solutions of a Hamiltonian system. Our…

Numerical Analysis · Mathematics 2015-03-17 Melvin Leok , Tatiana Shingel

We present both the Lagrangian and Hamiltonian procedures for treating higher-order equations of motion for mechanical models by adopting the Riemann-Liouville Fractional integral to describe their action. We point out and discuss its…

Classical Physics · Physics 2018-08-28 C. F. L. Godinho , Nelson Panza , J. A. Helayël Neto

We present an alternative numerical reconstruction algorithm for direct tomographic reconstruction of a sample refractive indices from the measured intensities of its far-field coherent diffraction patterns. We formulate the well-known…

Computational Physics · Physics 2019-02-06 T. Ramos , Bastian E. Grønager , Martin Skovgaard Andersen , J. W. Andreasen

Calibration of large-scale differential equation models to observational or experimental data is a widespread challenge throughout applied sciences and engineering. A crucial bottleneck in state-of-the art calibration methods is the…

Optimization and Control · Mathematics 2021-02-23 Jon Cockayne , Andrew B. Duncan

A new approach for analyzing waveguide junctions containing conductive cylindrical objects is proposed. The algorithm is based on mode matching technique using local projection functions, which improves the numerical conditioning of the…

Computational Engineering, Finance, and Science · Computer Science 2026-01-12 Malgorzata Warecka , Rafal Lech , Piotr Kowalczyk

We use the Landweber method for numerical simulations for the multiwave tomography problem with a reflecting boundary and compare it with the averaged time reversal method. We also analyze the rate of convergence and the dependence on the…

Analysis of PDEs · Mathematics 2016-04-21 Plamen Stefanov , Yang Yang

In recent years, levitated particles of optical traps in vacuum have shown enormous potential in precision sensor development and searching for new physics. The accuracy of the calibration relating the detected signal to absolute…

Instrumentation and Detectors · Physics 2022-03-08 Jianyu Yang , Nan Li , Xunmin Zhu , Ming Chen , Xingfan Chen , Cheng Liu , Jian Zhuang , Huizhu Hu

A statistical inference method is developed and tested for pairwise interacting systems whose degrees of freedom are continuous angular variables, such as planar spins in magnetic systems or wave phases in optics and acoustics. We…

Statistical Mechanics · Physics 2015-06-15 P. Tyagi , A. Pagnani , F. Antenucci , M. Ibáñez Berganza , L. Leuzzi
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