نتایج جستجو برای: singleton g riesz basis

تعداد نتایج: 814267  

Journal: :Journal of Approximation Theory 2009
Thomas Schlumprecht N. Sivakumar

Let λ be a positive number, and let (xj : j ∈ Z) ⊂ R be a fixed Riesz-basis sequence, namely, (xj) is strictly increasing, and the set of functions {R ∋ t 7→ ej : j ∈ Z} is a Riesz basis (i.e., unconditional basis) for L2[−π,π]. Given a function f ∈ L2(R) whose Fourier transform is zero almost everywhere outside the interval [−π, π], there is a unique square-summable sequence (aj : j ∈ Z), depe...

2007
Hongmei Zhang Fawang Liu F. W. Liu

In this paper, the space-time Riesz fractional partial differential equations with periodic conditions are considered. The equations are obtained from the integral partial differential equation by replacing the time derivative with a Caputo fractional derivative and the space derivative with Riesz potential. The fundamental solutions of the space Riesz fractional partial differential equation (...

2000
WAYNE LAWTON

Sufficient conditions for the convergence in distribution of an infinite convolution product μ1 ∗μ2 ∗ . . . of measures on a connected Lie group G with respect to left invariant Haar measure are derived. These conditions are used to construct distributions φ that satisfy Tφ = φ where T is a refinement operator constructed from a measure μ and a dilation automorphism A. The existence of A implie...

Journal: :IJWMIP 2014
S. Häuser B. Heise Gabriele Steidl

The only quadrature operator of order two on L2(R) which covaries with orthogonal transforms, in particular rotations is (up to the sign) the Riesz transform. This property was used for the construction of monogenic wavelets and curvelets. Recently, shearlets were applied for various signal processing tasks. Unfortunately, the Riesz transform does not correspond with the shear operation. In thi...

Journal: :SIAM J. Imaging Sciences 2013
John Paul Ward Kunal Narayan Chaudhury Michael Unser

The Riesz transform is a natural multidimensional extension of the Hilbert transform, and it has been the object of study for many years due to its nice mathematical properties. More recently, the Riesz transform and its variants have been used to construct complex wavelets and steerable wavelet frames in higher dimensions. The flip side of this approach, however, is that the Riesz transform of...

1999
Hideyuki Ishi

Riesz distributions are relatively invariant distributions supported by the closure of a homogeneous cone . In this paper, we clarify the positivity condition of Riesz distributions by relating it to the orbit structure of . Moreover each of the positive Riesz distributions is described explicitly as a measure on an orbit in .

2001
Peter G. Casazza Ole Christensen

AWeyl-Heisenberg frame {EmbTnag}m,n∈Z = {eg(·−na)}m,n∈Z for L2(R) allows every function f ∈ L2(R) to be written as an infinite linear combination of translated and modulated versions of the fixed function g ∈ L2(R). In the present paper we find sufficient conditions for {EmbTnag}m,n∈Z to be a frame for span{EmbTnag}m,n∈Z , which, in general, might just be a subspace of L2(R) . Even our conditio...

2013
JOHN PAUL WARD

The Riesz transform is a natural multi-dimensional extension of the Hilbert transform, and it has been the object of study for many years due to its nice mathematical properties. More recently, the Riesz transform and its variants have been used to construct complex wavelets and steerable wavelet frames in higher dimensions. The flip side of this approach, however, is that the Riesz transform o...

Journal: :Adv. Comput. Math. 2009
Rong-Qing Jia

In this paper we investigate spline wavelets on the interval with homogeneous boundary conditions. Starting with a pair of families of B-splines on the unit interval, we give a general method to explicitly construct wavelets satisfying the desired homogeneous boundary conditions. On the basis of a new development of multiresolution analysis, we show that these wavelets form Riesz bases of certa...

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