||Further bounds for Cebysev functional for power series in banach algebras via Grüss-Lupas type inequalities for p-norms
Silvestru Sever, Dragomir ,
Marius Valentin, Boldea ,
Mihail, MeganWada, Takeshi
34 , 2016-03 , 島根大学総合理工学研究科
Some Grüss-Lupas type inequalities for p-norms of sequences in Banach algebras are obtained. Moreover, if f(λ)=Σ^^∞__<n=0>α_nλ^n is a function defined by power series with complex coefficients and convergent on the open disk D(0,R)⊂C, R > 0 and x,y ∈ B, a Banach algebra, with xy = yx, then we also establish some new upper bounds for the norm of the Cebysev type differencef(λ)f(λxy) - f(λx)f(λy), λ ∈ D(0,R).These results build upon the earlier results obtained by the authors. Applications for some fundamental functions such as the exponential function and the resolvent function are provided as well.