Vector norm inequalities for power series of operators in Hilbert spaces

W.S. Cheung, S.S. Dragomir

In this paper, vector norm inequalities that provides upper bounds for the Lipschitz quantity || f(T)x-f(V)x|| for power series f(z) = n=0 anzn, bounded linear operators T, V on the Hilbert space H and vectors x ϵ H are established. Applications in relation to Hermite-Hadamard type inequalities and examples for elementary functions of interest are given as well.

Tbilisi Mathematical Journal, Vol. 7(2) (2014), pp. 21-34