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We present a unified group-theoretical derivation of the Continuous Wavelet Transform (CWT) on the circle $\mathbb S^1$ and the real line $\mathbb{R}$, following the general formalism of Coherent States (CS) associated to unitary square…

Mathematical Physics · Physics 2007-05-23 Manuel Calixto , Julio Guerrero

We consider the conformal group of the unit sphere $S^{n-1},$ the so-called proper Lorentz group Spin$^+(1,n),$ for the study of spherical continuous wavelet transforms (CWT). Our approach is based on the method for construction of general…

Representation Theory · Mathematics 2013-08-08 Milton Ferreira

In this paper, we have studied continuous fractional wavelet transform (CFrWT) in $n$-dimensional Euclidean space $\mathbb{R}^n$ with dilation parameter $\boldsymbol a=(a_{1},a_{2},\ldots,a_{n}),$ such that none of $a_{i}'s$ are zero.…

Functional Analysis · Mathematics 2019-12-20 Amit K. Verma , Bivek Gupta

We construct the Continuous Wavelet Transform (CWT) on the homogeneous space (Cartan domain) D_4=SO(4,2)/(SO(4)\times SO(2)) of the conformal group SO(4,2) (locally isomorphic to SU(2,2)) in 1+3 dimensions. The manifold D_4 can be mapped…

Mathematical Physics · Physics 2011-06-21 M. Calixto , E. Perez-Romero

While the Clifford (geometric) algebra Fourier Transform (CFT) is global, we introduce here the local Clifford (geometric) algebra (GA) wavelet concept. We show how for $n=2,3 (\mod 4)$ continuous $Cl_n$-valued admissible wavelets can be…

Rings and Algebras · Mathematics 2013-06-10 Eckhard Hitzer

In \cite{AV99}, Antoine and Vandergheynst propose a group-theoretic approach to continuous wavelet frames on the sphere. The frame is constructed from a single so-called admissible function by applying the unitary operators associated to a…

Functional Analysis · Mathematics 2024-07-11 S. Dahlke , F. De Mari , E. De Vito , M. Hansen , M. Hasannasab , M. Quellmalz , G. Steidl , G. Teschke

We consider the problem of characterizing the Sobolev wavefront set of a tempered distribution $u\in\mathcal{S}'(\mathbb{R}^{d})$ in terms of its continuous wavelet transform, with the latter being defined with respect to a suitably chosen…

Functional Analysis · Mathematics 2024-02-06 Hartmut Führ , Mahya Ghandehari

The main objective of this paper is to define the mother wavelet on local fields and study the continuous wavelet transform (CWT) and some of their basic properties. its inversion formula, the Parseval relation and associated convolution…

Functional Analysis · Mathematics 2015-01-30 Ashish Pathak

We study continuous wavelet transforms associated to matrix dilation groups giving rise to an irreducible square-integrable quasi-regular representation on ${\rm L}^2(\mathbb{R}^d)$. We first prove that these representations are integrable…

Functional Analysis · Mathematics 2013-08-22 Hartmut Führ

Continuous wavelet transforms arising from the quasiregular representation of a semidirect product of a vector group with a matrix group -- the so-called dilation group -- have been studied by various authors. Recently the attention has…

Mathematical Physics · Physics 2016-09-07 Hartmut Fuehr , Matthias Mayer

The analysis of gravitational-wave (GW) signals is one of the most challenging application areas of signal processing. Wavelet transforms are specially helpful in detecting and analyzing GW transients and several analysis pipelines are…

General Relativity and Quantum Cosmology · Physics 2024-05-27 Andrea Virtuoso , Edoardo Milotti

This paper presents a full catalogue, up to conjugacy and subgroups of finite index, of all matrix groups $H < {\rm GL}(3,\mathbb{R})$ that give rise to a continuous wavelet transform with associated irreducible quasi-regular…

Functional Analysis · Mathematics 2016-10-26 Bradley Currey , Hartmut Führ , Vignon Oussa

A traditional wavelet is a special case of a vector in a separable Hilbert space that generates a basis under the action of a system of unitary operators defined in terms of translation and dilation operations. A Coxeter/fractal-surface…

Functional Analysis · Mathematics 2007-10-22 David Larson , Peter Massopust

Single wavelet sets, and thus single wavelets, are shown to exist for the actions of all crystallographic groups on $\mathbb R^2$ under all integer dilations. Examples of such sets satisfying the additional requirement that they are finite…

Functional Analysis · Mathematics 2020-05-06 Kathy D. Merrill

We show how for $n=2,3 (\mod 4)$ continuous Clifford (geometric) algebra (GA) $Cl_n$-valued admissible wavelets can be constructed using the similitude group $SIM(n)$. We strictly aim for real geometric interpretation, and replace the…

Rings and Algebras · Mathematics 2013-06-10 Eckhard Hitzer

We demonstrate that the Plancherel transform for Type-I groups provides one with a natural, unified perspective for the generalized continuous wavelet transform, on the one hand, and for a class of Wigner functions, on the other. The…

Mathematical Physics · Physics 2007-05-23 S. Twareque Ali , Hartmut Fuehr , Anna E. Krasowska

The representation of solutions of Maxwell's equations as superpositions of scalar wavelets with vector coefficients developed earlier is generalized to wavelets with polarization, which are matrix-valued. The construction proceeds in four…

Mathematical Physics · Physics 2007-05-23 Gerald Kaiser

The application of the continuous wavelet transform to study of a wide class of physical processes with oscillatory dynamics is restricted by large central frequencies due to the admissibility condition. We propose an alternative…

Classical Analysis and ODEs · Mathematics 2014-10-09 Elena A. Lebedeva , Eugene B. Postnikov

We consider the problem of characterizing the wavefront set of a tempered distribution $u\in\mathcal{S}'(\mathbb{R}^{d})$ in terms of its continuous wavelet transform, where the latter is defined with respect to a suitably chosen dilation…

Functional Analysis · Mathematics 2014-12-24 Jonathan Fell , Hartmut Führ , Felix Voigtlaender

The dual-tree complex wavelet transform (DT-CWT) is known to exhibit better shift-invariance than the conventional discrete wavelet transform. We propose an amplitude-phase representation of the DT-CWT which, among other things, offers a…

Information Theory · Computer Science 2013-07-23 Kunal Narayan Chaudhury , Michael Unser
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