Sard's theorem for mappings between Fr\'echet manifolds

Abstract

In this paper we prove an infinite-dimensional version of Sard's theorem for Fr\'{e}chet manifolds. Let $ M $ and $ N $ be bounded Fr\'{e}chet manifolds such that the topologies of their model Fr\'{e}chet spaces are defined by metrics with absolutely convex balls. Let $ f: M \rightarrow N $ be an $ MC^k$-Lipschitz-Fredholm map with $ k > \max \lbrace {\Ind f,0} \rbrace $. Then the set of regular values of $ f $ is residual in $ N $.