Generalized-lush spaces and the Mazur–Ulam property
Tom 219 / 2013
Streszczenie
We introduce a new class of Banach spaces, called generalized-lush spaces (GL-spaces for short), which contains almost-CL-spaces, separable lush spaces (in particular, separable $C$-rich subspaces of $C(K)$), and even the two-dimensional space with hexagonal norm. We find that the space $C(K,E)$ of vector-valued continuous functions is a GL-space whenever $E$ is, and show that the set of GL-spaces is stable under $c_0$-, $l_1$- and $l_\infty $-sums. As an application, we prove that the Mazur–Ulam property holds for a larger class of Banach spaces, called local-GL-spaces, including all lush spaces and GL-spaces. Furthermore, we generalize the stability properties of GL-spaces to local-GL-spaces. From this, we can obtain many examples of Banach spaces having the Mazur–Ulam property.
