Journal of Linear and Topological Algebra

55-63

Authors: Mina Ettefagha and Sima Houdfar

In this paper by using some conditions, we show that the weak amenability of (2n)-th dual of a Banach algebra A for some n ⩾ 1 implies the weak amenability of A.

69-77

Authors: M. Nili Ahmadabadi

In this paper, a fundamentally new method, based on the definition, is introduced for numerical computation of eigenvalues, generalized eigenvalues and quadratic eigenvalues of matrices. Some examples are provided to show the accuracy and reliability of the proposed method. It is shown that the proposed method gives other sequences than that of existing methods but they still are convergent to the desired eigenvalues, generalized eigenvalues and quadratic eigenvalues of matrices. These examples show an interesting phenomenon in the procedure: The diagonal matrix that converges to eigenvalues gives them in decreasing order in the sense of absolute value. Appendices A to C provide Matlab codes that implement the

91-104

Authors: M. Amirfakhrian and F. Mohammad

In this paper, we represent an inexact inverse subspace iteration method for com- puting a few eigenpairs of the generalized eigenvalue problem Ax = Bx[Q. Ye and P. Zhang, Inexact inverse subspace iteration for generalized eigenvalue problems, Linear Algebra and its Application, 434 (2011) 1697-1715 ]. In particular, the linear convergence property of the inverse subspace iteration is preserved.