English

Banach-Stone Theorems for maps preserving common zeros

Functional Analysis 2009-06-02 v1

Abstract

Let XX and YY be completely regular spaces and EE and FF be Hausdorff topological vector spaces. We call a linear map TT from a subspace of C(X,E)C(X,E) into C(Y,F)C(Y,F) a \emph{Banach-Stone map} if it has the form Tf(y)=Sy(f(h(y))Tf(y) = S_{y}(f(h(y)) for a family of linear operators Sy:EFS_{y} : E \to F, yYy \in Y, and a function h:YXh: Y \to X. In this paper, we consider maps having the property: \cap^{k}_{i=1}Z(f_{i}) \neq\emptyset\iff\cap^{k}_{i=1}Z(Tf_{i}) \neq \emptyset, where Z(f)={f=0}Z(f) = \{f = 0\}. We characterize linear bijections with property (Z) between spaces of continuous functions, respectively, spaces of differentiable functions (including CC^{\infty}), as Banach-Stone maps. In particular, we confirm a conjecture of Ercan and \"Onal: Suppose that XX and YY are realcompact spaces and EE and FF are Hausdorff topological vector lattices (respectively, CC^{*}-algebras). Let T:C(X,E)C(Y,F)T: C(X,E) \to C(Y,F) be a vector lattice isomorphism (respectively, *-algebra isomorphism) such that Z(f) \neq\emptyset\iff Z(Tf) \neq\emptyset. Then XX is homeomorphic to YY and EE is lattice isomorphic (respectively, CC^{*}-isomorphic) to FF. Some results concerning the continuity of TT are also obtained.

Keywords

Cite

@article{arxiv.0906.0219,
  title  = {Banach-Stone Theorems for maps preserving common zeros},
  author = {Denny H. Leung and Wee-Kee Tang},
  journal= {arXiv preprint arXiv:0906.0219},
  year   = {2009}
}
R2 v1 2026-06-21T13:08:13.026Z