a1 Departamento de Matemáticas, Estadística y Computación, Universidad de Cantabria, Facultad de Ciencias, 39071 Santander, Spain e-mail: araujo@matesco.unican.es
Abstract
Given two subsets X and Y of
each with at least two points, we describe the surjective linear isometries between the spaces of functions of bounded variation BV(X) and BV(Y): namely, if T : BV(X) → BV(Y) is such an isometry, then there exist α
, |α| = 1, and a monotonic bijective map h : Y → X such that (Tf)(y) = αf(h(y)) for every f
BV(X) and every y
Y.
(Received October 01 1998)