English

Positively $p$-nuclear operators, positively $p$-integral operators and approximation properties

Functional Analysis 2021-01-19 v1

Abstract

In the present paper, we introduce and investigate a new class of positively pp-nuclear operators that are positive analogues of right pp-nuclear operators. One of our main results establishes an identification of the dual space of positively pp-nuclear operators with the class of positive pp-majorizing operators that is a dual notion of positive pp-summing operators. As applications, we prove the duality relationships between latticially pp-nuclear operators introduced by O. I. Zhukova and positively pp-nuclear operators. We also introduce a new concept of positively pp-integral operators via positively pp-nuclear operators and prove that the inclusion map from Lp(μ)L_{p^{*}}(\mu) to L1(μ)L_{1}(\mu)(μ\mu finite) is positively pp-integral. New characterizations of latticially pp-integral operators by O. I. Zhukova and positively pp-integral operators are presented and used to prove that an operator is latticially pp-integral (resp. positively pp-integral) precisely when its second adjoint is. Finally, we describe the space of positively pp^{*}-integral operators as the dual of the Υp\|\cdot\|_{\Upsilon_{p}}-closure of the subspace of finite rank operators in the space of positive pp-majorizing operators. Approximation properties, even positive approximation properties, are needed in establishing main identifications.

Keywords

Cite

@article{arxiv.2101.06363,
  title  = {Positively $p$-nuclear operators, positively $p$-integral operators and approximation properties},
  author = {Dongyang Chen and Amar Belacel and Javier Alejandro Chávez-Domínguez},
  journal= {arXiv preprint arXiv:2101.06363},
  year   = {2021}
}
R2 v1 2026-06-23T22:13:19.520Z