@article { author = {Ghaffari, Ali and Sahabi, Mohammad Bagher}, title = {Characterizations of amenable hypergroups}, journal = {Wavelet and Linear Algebra}, volume = {4}, number = {1}, pages = {1-9}, year = {2017}, publisher = {Vali-e-Asr university of Rafsanjan}, issn = {2383-1936}, eissn = {2476-3926}, doi = {10.22072/wala.2017.23365}, abstract = {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 characterizations of amenable hypergroups are given.}, keywords = {Amenability,Banach algebras,Hypergroup algebras,Left invariant mean,Topologically left invariant mean}, url = {https://wala.vru.ac.ir/article_23365.html}, eprint = {https://wala.vru.ac.ir/article_23365_e3e911df58170eb14ba5a4a8f162ef0c.pdf} } @article { author = {zare, Masoumeh and Kamyabi-Gol, Rajab ali and amiri, Zahra}, title = {Determination of subrepresentations of the standard higher dimensional shearlet group}, journal = {Wavelet and Linear Algebra}, volume = {4}, number = {1}, pages = {11-21}, year = {2017}, publisher = {Vali-e-Asr university of Rafsanjan}, issn = {2383-1936}, eissn = {2476-3926}, doi = {10.22072/wala.2017.23366}, abstract = {‎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.}, keywords = {‎‎ orbit,standard higher dimensional shearlet group,square-integrable representation‎}, url = {https://wala.vru.ac.ir/article_23366.html}, eprint = {https://wala.vru.ac.ir/article_23366_278253b8ba374cbd231b1cdf2dd51313.pdf} } @article { author = {Aghamollaei, Golamreza and Rezagholi, Sharifeh}, title = {On higher rank numerical hulls of normal matrices}, journal = {Wavelet and Linear Algebra}, volume = {4}, number = {1}, pages = {23-32}, year = {2017}, publisher = {Vali-e-Asr university of Rafsanjan}, issn = {2383-1936}, eissn = {2476-3926}, doi = {10.22072/wala.2017.47123.1080}, abstract = {‎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.}, keywords = {Rank-k numerical hulls‎,Joint rank-k numerical range‎,‎Polynomial numerical hull‎,‎basic circulant matrix}, url = {https://wala.vru.ac.ir/article_23367.html}, eprint = {https://wala.vru.ac.ir/article_23367_ebbd946a37c2e6eee2b03af2d07bdd99.pdf} } @article { author = {Alijani, Azadeh}, title = {A-B-imprimitivity bimodule frames}, journal = {Wavelet and Linear Algebra}, volume = {4}, number = {1}, pages = {33-41}, year = {2017}, publisher = {Vali-e-Asr university of Rafsanjan}, issn = {2383-1936}, eissn = {2476-3926}, doi = {10.22072/wala.2017.47173.1081}, abstract = {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.}, keywords = {A-B-imprimitivity bimodule Frame,Frame,Hilbert A-B-imprimitivity bimodule,Semi-tight frame}, url = {https://wala.vru.ac.ir/article_25011.html}, eprint = {https://wala.vru.ac.ir/article_25011_27d211d588301e528d336de1c9906af6.pdf} } @article { author = {Zangiabadi, Mostafa and Afshin, Hamid Reza}, title = {Some results on the block numerical range}, journal = {Wavelet and Linear Algebra}, volume = {4}, number = {1}, pages = {43-51}, year = {2017}, publisher = {Vali-e-Asr university of Rafsanjan}, issn = {2383-1936}, eissn = {2476-3926}, doi = {10.22072/wala.2017.51809.1088}, abstract = {The main results of this paper are generalizations of classical results from the numerical range to the block numerical range. A different and simpler proof for the Perron-Frobenius theory on the block numerical range of an irreducible nonnegative matrix is given. In addition, the Wielandt's lemma and the Ky Fan's theorem on the block numerical range are extended.}, keywords = {block numerical range,nonnegative matrix,numerical range,Perron-Frobenius theory}, url = {https://wala.vru.ac.ir/article_25012.html}, eprint = {https://wala.vru.ac.ir/article_25012_c4ff34a31d45ccb5ef9f7bc71791f5b0.pdf} } @article { author = {Mohammadi, Fakhrodin and Ciancio, Armando}, title = {Wavelet‎-based numerical ‎method‎ ‎‎‎‎for solving fractional integro-differential equation with a weakly singular ‎kernel}, journal = {Wavelet and Linear Algebra}, volume = {4}, number = {1}, pages = {53-73}, year = {2017}, publisher = {Vali-e-Asr university of Rafsanjan}, issn = {2383-1936}, eissn = {2476-3926}, doi = {10.22072/wala.2017.52567.1091}, abstract = {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.}, keywords = {Fractional integro-differential equation,Weakly singular integral kernel,Collocation method‎, ‎Error estimates}, url = {https://wala.vru.ac.ir/article_29387.html}, eprint = {https://wala.vru.ac.ir/article_29387_eba4b5ca1c590ac187007f13d8603195.pdf} }