Research ArticleOpen accessEvery word in the titleOn Numerical Ranges of Nilpotent Elements of C*-AlgebraA. Abdollahi, M. T. Heydari, M. MoosaviProblem statement: Let A be a C*-algebra with unit 1. For each a∈A, let V(a), v(a) v0(a) and denote its numerical range, numerical radius and the distance from the origin to the boundary of its numerical range, respectively. Approach: If a is a nilpotent element of A with the power of nilpotency n, i.e., an = 0 and v(a) = … …Journal of Mathematics and Statistics, Vol. 5, Issue 4 · 31 Dec 2009 · 7,437 accessesView PDFCite