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In image reconstruction there are techniques that use analytical formulae for the Radon transform to recover an image from a continuum of data. In practice, however, one has only discrete data available. Thus one often resorts to sampling…

Functional Analysis · Mathematics 2011-08-30 Isaac Pesenson , Eric Grinberg

The star transform is a generalized Radon transform mapping a function on $\mathbb{R}^n$ to the function whose value at a point is the integral along a union of rays emanating from the point in a fixed set of directions, called branch…

Algebraic Geometry · Mathematics 2025-07-31 Gaik Ambartsoumian , Asher Auel , Mohammad Javad Latifi Jebelli

For the accurate representation and reconstruction of band-limited signals on the sphere, an optimal-dimensionality sampling scheme has been recently proposed which requires the optimal number of samples equal to the number of degrees of…

Information Theory · Computer Science 2017-09-11 Wajeeha Nafees , Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

In this work, we study a set of generalized Radon transforms over symmetric $m$-tensor fields in $\mathbb{R}^n$. The longitudinal/transversal Radon transform and corresponding weighted integral transforms for symmetric $m$-tensor field are…

Analysis of PDEs · Mathematics 2025-02-05 Anuj Abhishek , Rohit Kumar Mishra , Chandni Thakkar

In a recent paper, we analyzed the properties of a new kind of spherical wavelets (called needlets) for statistical inference procedures on spherical random fields; the investigation was mainly motivated by applications to cosmological…

Statistics Theory · Mathematics 2009-06-12 P. Baldi , G. Kerkyacharian , D. Marinucci , D. Picard

This article provides a novel and simple range description for the spherical mean transform of functions supported in the unit ball of an odd dimensional Euclidean space. The new description comprises a set of symmetry relations between the…

Classical Analysis and ODEs · Mathematics 2024-07-18 Divyansh Agrawal , Gaik Ambartsoumian , Venkateswaran P. Krishnan , Nisha Singhal

The principal aim of the present paper is to develop the theory of Gelfand pairs on the symmetric group in order to define and study the horocyclic Radon transform on this group. We also find a simple inversion formula for the Radon…

Group Theory · Mathematics 2007-05-23 Omar El Fourchi , Adil Echchelh

Many modern imaging and remote sensing applications require reconstructing a function from spherical averages (mean values). Examples include photoacoustic tomography, ultrasound imaging or SONAR. Several formulas of the back-projection…

Analysis of PDEs · Mathematics 2015-01-20 M. Haltmeier

Faraday Rotation Measure (RM) Synthesis, as a method for analyzing multi-channel observations of polarized radio emission to investigate galactic magnetic fields structures, requires the definition of complex polarized intensity in the…

Astrophysics of Galaxies · Physics 2015-05-14 P. Frick , D. Sokoloff , R. Stepanov , R. Beck

Let G/H be a hyperbolic space over R C or H, and let K be a maximal compact subgroup of G. Let D denote a certain explicit invariant differential operator, such that the non-cuspidal discrete series belong to the kernel of D. For any…

Representation Theory · Mathematics 2013-03-04 Nils Byrial Andersen , Mogens Flensted--Jensen

We develop a method for the accurate reconstruction of non-bandlimited finite rate of innovation signals on the sphere. For signals consisting of a finite number of Dirac functions on the sphere, we develop an annihilating filter based…

Information Theory · Computer Science 2016-12-20 Yahya Sattar , Zubair Khalid , Rodney A. Kennedy

We investigate here a generalized construction of spherical wavelets/needlets which admits extra-flexibility in the harmonic domain, i.e., it allows the corresponding support in multipole (frequency) space to vary in more general forms than…

Probability · Mathematics 2021-09-14 Claudio Durastanti , Domenico Marinucci , Anna Paola Todino

Tomography is a central tool in medical applications, allowing doctors to investigate patients' interior features. The Radon transform (in two dimensions) is commonly used to model the measurement process in parallel-beam CT. Suitable…

Numerical Analysis · Mathematics 2026-02-27 Richard Huber

Radon transform is widely used in physical and life sciences and one of its major applications is the X-ray computed tomography (X-ray CT), which is significant in modern health examination. The Radon inversion or image reconstruction is…

Computer Vision and Pattern Recognition · Computer Science 2018-08-10 Ji He , Jianhua Ma

We describe the construction of a spherical wavelet analysis through the inverse stereographic projection of the Euclidean planar wavelet framework, introduced originally by Antoine and Vandergheynst and developed further by Wiaux et al.…

Astrophysics · Physics 2011-10-28 J. D. McEwen , M. P. Hobson , D. J. Mortlock , A. N. Lasenby

Light injected into a spherical dielectric body may be confined very efficiently via the mechanism of total internal reflection. The frequencies that are most confined are called resonances. If the shape of the body deviates from the…

Optics · Physics 2020-09-30 Julius Gohsrich

Single photon emission computed tomography (SPECT) is a well established clinical tool for functional imaging. A limitation of current SPECT systems is the use of mechanical collimation, where only a small fraction of the emitted photons is…

Numerical Analysis · Mathematics 2016-07-05 Sunghwan Moon , Markus Haltmeier

Recently a hypothesis explaining the non-resonant mechanism of subwavelength imaging granted by a dielectric microsphere has been suggested. In accordance to the hypothesis, the far-field image of a subwavelength scatterer strongly coupled…

Optics · Physics 2021-07-28 R. Heydarian , C. Simovski

In the present paper, a construction of spin weighted spherical wavelets is presented. It is based on approximate identities, the wavelets are defined for a continuous set of parameters, and the wavelet transform is invertible directly by…

Functional Analysis · Mathematics 2018-04-16 Ilona Iglewska-Nowak

Inversion of Radon transforms is the mathematical foundation of many modern tomographic imaging modalities. In this paper we study a conical Radon transform, which is important for computed tomography taking Compton scattering into account.…

Numerical Analysis · Mathematics 2016-07-19 Markus Haltmeier