Operator Valued Series and Vector Valued Multiplier Spaces

Document Type : Research Articles

Author

Mathematics Department, New Mexico State University Las Cruces‎, ‎NM 88003,USA

Abstract

‎Let X,Y be normed spaces with L(X,Y) the space of continuous‎
‎linear operators from X into Y‎. ‎If Tj is a sequence in L(X,Y),‎
‎the (bounded) multiplier space for the series sumTj is defined to be‎
[
‎M^{infty}(sum T_{j})={{x_{j}}in l^{infty}(X):sum_{j=1}^{infty}%‎
‎T_{j}x_{j}text{ }converges}‎
‎]‎
‎and the summing operator S:Minfty(sumTj)rightarrowY associated‎
‎with the series is defined to be S(xj)=sumj=1inftyTjxj.‎
‎In the scalar case the summing operator has been used to characterize‎
‎completeness‎, ‎weakly unconditionall Cauchy series‎, ‎subseries and absolutely‎
‎convergent series‎. ‎In this paper some of these results are generalized to the‎
‎case of operator valued series The corresponding space of weak multipliers‎
‎is also considered.‎

Keywords