2019-12-07T17:16:46Z
http://wala.vru.ac.ir/?_action=export&rf=summon&issue=4342
Wavelet and Linear Algebra
WALA
2383-1936
2383-1936
2017
4
1
Characterizations of amenable hypergroups
Ali
Ghaffari
Mohammad Bagher
Sahabi
Let $K$ be a locally compact hypergroup with left Haar measure and let $L^1(K)$ be the complex Lebesgue space associated with it. Let $L^infty(K)$ be the dual of $L^1(K)$. The purpose of this paper is to present some necessary and sufficient conditions for $L^infty(K)^*$ to have a topologically left invariant mean. Some<br /> characterizations of amenable hypergroups are given.
Amenability
Banach algebras
Hypergroup algebras
Left invariant mean
Topologically left invariant mean
2017
08
01
1
9
http://wala.vru.ac.ir/article_23365_e3e911df58170eb14ba5a4a8f162ef0c.pdf
Wavelet and Linear Algebra
WALA
2383-1936
2383-1936
2017
4
1
Determination of subrepresentations of the standard higher dimensional shearlet group
Masoumeh
zare
Rajab ali
Kamyabi-Gol
Zahra
amiri
This paper is devoted to definition standard higher dimension shearlet group $ mathbb{S} = mathbb{R}^{+} times mathbb {R}^{n-1} times mathbb {R}^{n} $ and determination of square integrable subrepresentations of this group. Also we give a characterisation of admissible vectors associated to the Hilbert spaces corresponding to each su brepresentations.
orbit
standard higher dimensional shearlet group
square-integrable representation
2017
08
01
11
21
http://wala.vru.ac.ir/article_23366_278253b8ba374cbd231b1cdf2dd51313.pdf
Wavelet and Linear Algebra
WALA
2383-1936
2383-1936
2017
4
1
On higher rank numerical hulls of normal matrices
Golamreza
Aghamollaei
Sharifeh
Rezagholi
In this paper, some algebraic and geometrical properties of the rank$-k$ numerical hulls of normal matrices are investigated. A characterization of normal matrices whose rank$-1$ numerical hulls are equal to their numerical range is given. Moreover, using the extreme points of the numerical range, the higher rank numerical hulls of matrices of the form $A_1 oplus i A_2$, where $A_1$ and $A_2$ are Hermitian, are investigated. The higher rank numerical hulls of the basic circulant matrix are also studied.
Rank-k numerical hulls
Joint rank-k numerical range
Polynomial numerical hull
basic circulant matrix
2017
08
01
23
32
http://wala.vru.ac.ir/article_23367_ebbd946a37c2e6eee2b03af2d07bdd99.pdf
Wavelet and Linear Algebra
WALA
2383-1936
2383-1936
2017
4
1
A-B-imprimitivity bimodule frames
Azadeh
Alijani
Frames in Hilbert bimodules are a special case of frames in Hilbert C*-modules. The paper considers A-frames and B-frames and their relationship in a Hilbert A-B-imprimitivity bimodule. Also, it is given that every frame in Hilbert spaces or Hilbert C*-modules is a semi-tight frame. A relation between A-frames and K(H_B)-frames is obtained in a Hilbert A-B-imprimitivity bimodule. Moreover, the last part of the paper investigates dual of an A-frame and a B-frame and presents a common property for all duals of a frame in a Hilbert A-B-imprimitivity bimodule.
A-B-imprimitivity bimodule Frame
Frame
Hilbert A-B-imprimitivity bimodule
Semi-tight frame
2017
08
01
33
41
http://wala.vru.ac.ir/article_25011_27d211d588301e528d336de1c9906af6.pdf
Wavelet and Linear Algebra
WALA
2383-1936
2383-1936
2017
4
1
Some results on the block numerical range
Mostafa
Zangiabadi
Hamid Reza
Afshin
The main results of this paper are generalizations of classical results from the numerical range to the block numerical range.<br /> A different and simpler proof for the Perron-Frobenius theory on the block numerical range of an irreducible nonnegative matrix is given.<br /> In addition, the Wielandt's lemma and the Ky Fan's theorem on the block numerical range are extended.
block numerical range
nonnegative matrix
numerical range
Perron-Frobenius theory
2017
08
01
43
51
http://wala.vru.ac.ir/article_25012_c4ff34a31d45ccb5ef9f7bc71791f5b0.pdf
Wavelet and Linear Algebra
WALA
2383-1936
2383-1936
2017
4
1
Wavelet-based numerical method for solving fractional integro-differential equation with a weakly singular kernel
Fakhrodin
Mohammadi
Armando
Ciancio
This paper describes and compares application of wavelet basis and Block-Pulse functions (BPFs) for solving fractional integro-differential equation (FIDE) with a weakly singular kernel. First, a collocation method based on Haar wavelets (HW), Legendre wavelet (LW), Chebyshev wavelets (CHW), second kind Chebyshev wavelets (SKCHW), Cos and Sin wavelets (CASW) and BPFs are presented for driving approximate solution FIDEs with a weakly singular kernel. Error estimates of all proposed numerical methods are given to test the convergence and accuracy of the method. A comparative study of accuracy and computational time for the presented techniques is given.
Fractional integro-differential equation
Weakly singular integral kernel
Collocation method, Error estimates
2017
08
01
53
73
http://wala.vru.ac.ir/article_29387_eba4b5ca1c590ac187007f13d8603195.pdf