The Bishop-Phelps-Bollob\'as property for compact operators

TL;DR

This paper investigates the Bishop-Phelps-Bollobás property for compact operators, establishing conditions under which it transfers from sequence spaces to various function spaces, with applications to Banach space theory.

Contribution

The paper introduces abstract techniques to extend the BPBp for compact operators from sequence spaces to function spaces, providing new transfer results and applications in Banach space theory.

Findings

BPBp for compact operators transfers from (c0,Y) to (C0(L),Y)

BPBp holds for (L1(μ,X),Y) when X* has Radon-Nikodym property

BPBp extends to (X,Lp(μ,Y)) and (X,L∞(μ,Y)) under certain conditions

Abstract

We study the Bishop-Phelps-Bollob\'as property (BPBp for short) for compact operators. We present some abstract techniques which allows to carry the BPBp for compact operators from sequence spaces to function spaces. As main applications, we prove the following results. Let $X$, $Y$ be Banach spaces. If $(c_0,Y)$ has the BPBp for compact operators, then so do $(C_0(L),Y)$ for every locally compact Hausdorff topological space $L$ and $(X,Y)$ whenever $X^*$ is isometrically isomorphic to $\ell_1$. If $X^*$ has the Radon-Nikod\'ym property and $(\ell_1(X),Y)$ has the BPBp for compact operators, then so does $(L_1(\mu,X),Y)$ for every positive measure $\mu$; as a consequence, $(L_1(\mu,X),Y)$ has the the BPBp for compact operators when $X$ and $Y$ are finite-dimensional or $Y$ is a Hilbert space and $X=c_0$ or $X=L_p(\nu)$ for any positive measure $\nu$ and $1< p< \infty$. For $1\leqslant p <\infty$, if $(X,\ell_p(Y))$ has the BPBp for compact operators, then so does $(X,L_p(\mu,Y))$ for every positive measure $\mu$ such that $L_1(\mu)$ is infinite-dimensional. If $(X,Y)$ has the BPBp for compact operators, then so do $(X,L_\infty(\mu,Y))$ for every $\sigma$-finite positive measure $\mu$ and $(X,C(K,Y))$ for every compact Hausdorff topological space $K$.