Mohammad Sal Moslehian   Masaru Tominaga   Kichi-Suke Saito   
LINEAR ALGEBRA AND ITS APPLICATIONS 435(4) 823-829 2011年8月 [査読有り]
Let C(p) be the Schatten p-class for p > 0. Generalizations of the parallelogram law for the Schatten 2-norms have been given in the following form: if A = {A(1),A(2),...,A(n)} and B = {B1, B2,..., B(n)} are two sets of operators in C(2), then
...
Chi-Kwong Li   Yiu-Tung Poon   Masaru Tominaga   
LINEAR & MULTILINEAR ALGEBRA 59(10) 1077-1104 2011年 [査読有り]
A bounded linear operator acting on a Hilbert space is a generalized quadratic operator if it has an operator matrix of the form
[aI cI dT* bI]
It reduces to a quadratic operator if d = 0. In this article, spectra, norms and various kinds of numer...
LINEAR ALGEBRA AND ITS APPLICATIONS 432(12) 3258-3264 2010年7月 [査読有り]
Dunkl and Williams showed that for any nonzero elements x, y in a normed linear space X
parallel to x/parallel to x parallel to - y/parallel to y parallel to parallel to <= 4 parallel to x - y parallel to/parallel to x parallel to + parallel to...