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Brushlet characterization of the Hardy space H1(R) and the space BMO.

Lasse Borup (2005)

Collectanea Mathematica

A typical wavelet system constitutes an unconditional basis for various function spaces -Lebesgue, Besov, Triebel-Lizorkin, Hardy, BMO. One of the main reasons is the frequency localization of an element from such a basis. In this paper we study a wavelet-type system, called a brushlet system. In [3] it was noticed that brushlets constitute unconditional bases for classical function spaces such as the Triebel-Lizorkin and Besov spaces. In this paper we study brushlet expansions of functions in the...

Calderón's conditions and wavelets.

Ziemowit Rzeszotnik (2001)

Collectanea Mathematica

The paper presents the proof of the fact that the discrete Calderón condition characterizes the completeness of an orthonormal wavelet basis.

Calderón-Zygmund operators and unconditional bases of weighted Hardy spaces

J. García-Cuerva, K. Kazarian (1994)

Studia Mathematica

We study sufficient conditions on the weight w, in terms of membership in the A p classes, for the spline wavelet systems to be unconditional bases of the weighted space H p ( w ) . The main tool to obtain these results is a very simple theory of regular Calderón-Zygmund operators.

Carleson measures, trees, extrapolation, and T(b) theorems.

Pascal Auscher, Steve Hofmann, Camil Muscalu, Terence Tao, Christoph Thiele (2002)

Publicacions Matemàtiques

The theory of Carleson measures, stopping time arguments, and atomic decompositions has been well-established in harmonic analysis. More recent is the theory of phase space analysis from the point of view of wave packets on tiles, tree selection algorithms, and tree size estimates. The purpose of this paper is to demonstrate that the two theories are in fact closely related, by taking existing results and reproving them in a unified setting. In particular we give a dyadic version of extrapolation...

Characterization of Bessel sequences.

M. Laura Arias, Gustavo Corach, Miriam Pacheco (2007)

Extracta Mathematicae

Let H be a separable Hilbert space, L(H) be the algebra of all bounded linear operators of H and Bess(H) be the set of all Bessel sequences of H. Fixed an orthonormal basis E = {ek}k∈N of H, a bijection αE: Bess(H) → L(H) can be defined. The aim of this paper is to characterize α-1E (A) for different classes of operators A ⊆ L(H). In particular, we characterize the Bessel sequences associated to injective operators, compact operators and Schatten p-classes.

Characterization of low pass filters in a multiresolution analysis

A. San Antolín (2009)

Studia Mathematica

We characterize the low pass filters associated with scaling functions of a multiresolution analysis in a general context, where instead of the dyadic dilation one considers the dilation given by a fixed linear invertible map A: ℝⁿ → ℝⁿ such that A(ℤⁿ) ⊂ ℤⁿ and all (complex) eigenvalues of A have modulus greater than 1. This characterization involves the notion of filter multiplier of such a multiresolution analysis. Moreover, the paper contains a characterization of the measurable functions which...

Characterizations of Gabor Systems via the Fourier transform.

Wojciech Czaja (2000)

Collectanea Mathematica

We give characterizations of orthogonal families, tight frames and orthonormal bases of Gabor systems. The conditions we propose are stated in terms of equations for the Fourier transforms of the Gabor system's generating functions.

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