English
Related papers

Related papers: Inequalities for Nonuniform Wavelet Frames

200 papers

In this paper we study the linear wave equation on an $n$-dimensional spatial domain. We show that there is a boundary triplet associated to the undamped wave equation. This enables us to characterise all boundary conditions for which the…

Optimization and Control · Mathematics 2015-11-09 Mikael Kurula , Hans Zwart

An asymmetric pair of coupled nonlinear Schr{\"o}dinger (CNLS) equations has been derived through a multiscale perturbation method applied to a plasma fluid model, in which two wavepackets of distinct carrier wavenumbers and amplitudes are…

Plasma Physics · Physics 2024-03-22 N. Lazarides , Giorgos P. Veldes , D. J. Frantzeskakis , Ioannis Kourakis

In this paper we show that there exists a new symmetry in the relativistic wave equation for a scalar field in arbitrary dimensions. This symmetry is related to redefinitions of the metric tensor which implement a map between non-equivalent…

General Relativity and Quantum Cosmology · Physics 2012-08-29 F. T. Falciano , E. Goulart

The nondecimated or translation-invariant wavelet transform (NDWT) is a central tool in classical multiscale signal analysis, valued for its stability, redundancy, and shift invariance. This paper develops two complementary quantum…

Quantum Physics · Physics 2025-12-29 Brani Vidakovic

We give a constructive proof for the superbosonization formula for invariant random matrix ensembles, which is the supersymmetry analog of the theory of Wishart matrices. Formulas are given for unitary, orthogonal and symplectic symmetry,…

Statistical Mechanics · Physics 2007-11-15 Hans-Jürgen Sommers

We emulate the Rademacher functions on any non-commutative compact group requiring the resulting system to have pairwise disjoint spectra.

Group Theory · Mathematics 2007-05-23 Javier Parcet

The paper develops theory of covariant transform, which is inspired by the wavelet construction. It was observed that many interesting types of wavelets (or coherent states) arise from group representations which are not square integrable…

Functional Analysis · Mathematics 2011-04-07 Vladimir V. Kisil

In this work we study families of pairs of window functions and lattices which lead to Gabor frames which all possess the same frame bounds. To be more precise, for every generalized Gaussian $g$, we will construct an uncountable family of…

Functional Analysis · Mathematics 2018-06-12 Markus Faulhuber

We demonstrate experimentally the tunable control of the joint spectrum, i.e. waveform and degree of frequency correlations, of paired photons generated in spontaneous parametric downconversion. This control is mediated by the spatial shape…

We report a general description of quasi-phase-matched parametric process in nonlinear photonic crystals (NLPC) by extending the conventional X-ray diffraction theory in solids. Under the virtual wave approximation, phase-matching resonance…

Optics · Physics 2015-05-13 H. C. Guo , Y. Q. Qin , G. J. You , W. M. Liu , S. H. Tang

The nonlinear Fourier transform has the potential to overcome limits on performance and achievable data rates which arise in modern optical fiber communication systems when nonlinear interference is treated as noise. The periodic nonlinear…

Signal Processing · Electrical Eng. & Systems 2020-12-24 Jan-Willem Goossens , Hartmut Hafermann , Yves Jaouën

A non-decimated wavelet transform (NDWT) is a popular version of wavelet transforms because of its many advantages in applications. The inherent redundancy of this transform proved beneficial in tasks of signal denoising and scaling…

Applications · Statistics 2016-04-26 Minkyoung Kang , Brani Vidakovic

We explore various models for the pattern forming instability in a laser-driven cloud of cold two-level atoms with a plane feedback mirror. Focus is on the combined treatment of nonlinear propagation in a diffractively thick medium and the…

Atomic Physics · Physics 2016-06-16 W. J. Firth , I. Krešić , G. Labeyrie , A. Camara , P. Gomes , T. Ackemann

Generalized shift-invariant (GSI) systems, originally introduced by Hern\'andez, Labate & Weiss and Ron & Shen, provide a common frame work for analysis of Gabor systems, wavelet systems, wave packet systems, and other types of structured…

Functional Analysis · Mathematics 2016-10-14 Ole Christensen , Marzieh Hasannasab , Jakob Lemvig

Two scaling functions $\varphi_A$ and $\varphi_B$ for Parseval frame wavelets are algebraically isomorphic, $\varphi_A \simeq \varphi_B$, if they have matching solutions to their (reduced) isomorphic systems of equations. Let $A$ and $B$ be…

Functional Analysis · Mathematics 2019-04-16 Xingde Dai , Wei Huang

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

Wavelets are closely related to the Schr\"odinger's wave functions and the interpretation of Born. Similarly to the appearance of atomic orbital, it is proposed to combine anti-symmetric wavelets into orbital wavelets. The proposed approach…

Signal Processing · Electrical Eng. & Systems 2020-10-02 H. M. de Oliveira , V. V. Vermehren , R. J. Cintra

In this paper we introduce a new localization framework for wavelet transforms, such as the 1D wavelet transform and the Shearlet transform. Our goal is to design nonadaptive window functions that promote sparsity in some sense. For that,…

Information Theory · Computer Science 2018-07-10 Ron Levie , Nir Sochen

In non-diagonal conformal models, the boundary fields are not directly related to the bulk spectrum. We illustrate some of their features by completing previous work of Lewellen on sewing constraints for conformal theories in the presence…

High Energy Physics - Theory · Physics 2009-10-30 Gianfranco Pradisi , Augusto Sagnotti , Yassen S. Stanev

The orthonormal basis generated by a wavelet of $L^2(\mathbb R)$ has poor frequency localization. To overcome this disadvantage Coifman, Meyer, and Wickerhauser constructed wavelet packets. We extend this concept to the higher dimensions…

Functional Analysis · Mathematics 2007-05-23 Biswaranjan Behera