Coarse version of the Banach–Stone theorem

Abstract

We show that if there exists a Lipschitz homeomorphism T between the nets in the Banach spaces C(X) and C(Y) of continuous real valued functions on compact spaces X and Y, then the spaces X and Y are homeomorphic provided l(T)×l(T−1)<65. By l(T) and l(T−1) we denote the Lipschitz constants of the maps T and T−1. This improves the classical result of Jarosz and the recent result of Dutrieux and Kalton where the constant obtained is 1716. We also estimate the distance of the map T from the isometry of the spaces C(X) and C(Y).