English
Related papers

Related papers: Inversion of the Abel equation for toroidal densit…

200 papers

We propose an approach to infer large-scale heterogeneities within a small celestial body from measurements of its gravitational potential, provided for instance by spacecraft radio-tracking. The non-uniqueness of the gravity inversion is…

Earth and Planetary Astrophysics · Physics 2023-11-10 Alfonso Caldiero , Sébastien Le Maistre

Since the early 1970s, inversion techniques have become the most useful tool for inferring the magnetic, dynamic, and thermodynamic properties of the solar atmosphere. The intrinsic model dependence makes it necessary to formulate specific…

Solar and Stellar Astrophysics · Physics 2016-12-07 Jose Carlos del Toro Iniesta , Basilio Ruiz Cobo

This paper concerns the reconstruction of a diffusion coefficient in an elliptic equation from knowledge of several power densities. The power density is the product of the diffusion coefficient with the square of the modulus of the…

Analysis of PDEs · Mathematics 2012-03-07 Guillaume Bal , Eric Bonnetier , Francois Monard , Faouzi Triki

In this article, we propose a new three parameter distribution by compounding negative binomial with reciprocal inverse Gaussian model called negative binomial-reciprocal inverse Gaussian distribution. This model is tractable with some…

Methodology · Statistics 2019-06-10 Ishfaq Shah Ahmad , Anwar Hassan , Peer Bilal Ahmad

Correlated ${\cal G}$ distributions can be used to describe the clutter seen in images obtained with coherent illumination, as is the case of B-scan ultrasound, laser, sonar and synthetic aperture radar (SAR) imagery. These distributions…

Methodology · Statistics 2012-07-10 O. H. Bustos , A. G. Flesia , A. C. Frery , M. M. Lucini

We study the angle-resolved spontaneous emission of near-infrared light sources in 3D photonic crystals over a wavelength range from 1200 to 1550 nm. To this end PbSe quantum dots are used as light sources inside titania inverse opal…

Optics · Physics 2014-12-23 B. H. Husken , A. F. Koenderink , W. L. Vos

The direct gravimetry problem is solved using the subdivision of each body of a deposit into a set of vertical adjoining bars, and in the inverse problem each body of a deposit is modeled by a uniform ellipsoid of revolution (spheroid).…

Numerical Analysis · Mathematics 2015-08-19 Valery Sizikov

An analytical description of arbitrary strongly aberrated axially symmetric focusing is developed. This is done by matching the solution of geometrical optics with a wave pattern which is universal for the underlying ray structure. The…

Optics · Physics 2007-05-23 Johannes Kofler , Nikita Arnold

We propose a tomographic method to reconstruct the optical properties of a highly-scattering medium from incoherent acousto-optic measurements. The method is based on the solution to an inverse problem for the diffusion equation and makes…

Optics · Physics 2015-05-14 Guillaume Bal , John C Schotland

Doppler reflectometry is considered in slab plasma model in the frameworks of analytical theory. The diagnostics locality is analyzed for both regimes: linear and nonlinear in turbulence amplitude. The toroidal antenna focusing of probing…

Plasma Physics · Physics 2007-05-23 Evgeniy Gusakov , Alexander Surkov

We discuss the implementation of Bayesian inversion methods in order to recover the properties of the intergalactic medium from observations of the neutral hydrogen Lyman-$\alpha$ absorptions observed in the spectra of high redshift quasars…

Astrophysics · Physics 2009-11-06 C. Pichon , J. L. Vergely , E. Rollinde , S. Colombi , P. Petitjean

The simple reflection of a light beam of finite transverse extent from a homogenous interface gives rise to a surprisingly large number of subtle shifts and deflections which can be seen as diffractive corrections to the laws of geometrical…

Optics · Physics 2012-11-15 Jörg B Götte , Mark R Dennis

For quantitative seismic imaging, iterative least-squares reverse time migration is the recommended approach. The existence of an inverse of the forward modelling operator would considerably reduce the number of required iterations. In the…

Geophysics · Physics 2020-12-11 Milad Farshad , Hervé Chauris

Access to the transverse spin of light has unlocked new regimes in topological photonics and optomechanics. To achieve the transverse spin of nonzero longitudinal fields, various platforms that derive transversely confined waves based on…

Optics · Physics 2018-05-23 Xianji Piao , Sunkyu Yu , Namkyoo Park

Let $X_1,...,X_n$ be $n$ independent unbounded real random variables which have common, roughly speaking, light-tailed type distribution. Denote by $S_1^n$ their sum and by $\pi^{a_n}$ the tilted density of $X_1$, where $a_n…

Probability · Mathematics 2013-02-07 Zhansheng Cao

Computed Tomography (CT) reconstruction of objects with cylindrical symmetry can be performed with a single projection. When the measured rays are parallel, and the axis of symmetry is perpendicular to the optical axis, the data can be…

Medical Physics · Physics 2024-10-15 Kyle M. Champley , Ibrahim Oksuz , Matthew G. Bisbee , Joseph W. Tringe , Brian Maddox

Atmospheric inverse modelling is a method for reconstructing historical fluxes of green-house gas between land and atmosphere, using observed atmospheric concentrations and an atmospheric tracer transport model. The small number of observed…

Applications · Statistics 2019-07-08 Unn Dahlen , Johan Linström , Marko Scholze

In this work, we derived formulae concerning the electric and magnetic field characteristics of a focused radially polarized Gaussian vector beam. Such a beam is consistent with Maxwell's equations contrary to plane waves having uniform…

Optics · Physics 2024-06-04 László Pálfalvi , Zerihun Tadele Godana , János Hebling

The inverse problem of backward diffusion is known to be ill-posed and highly unstable. Backward diffusion processes appear naturally in image enhancement and deblurring applications. It is therefore greatly desirable to establish a…

Numerical Analysis · Mathematics 2020-06-18 Leif Bergerhoff , Marcelo Cárdenas , Joachim Weickert , Martin Welk

Reconstructing images from ill-posed inverse problems often utilizes total variation regularization in order to recover discontinuities in the data while also removing noise and other artifacts. Total variation regularization has been…

Analysis of PDEs · Mathematics 2018-08-15 Linan Zhang , Hayden Schaeffer