Verbindungsregeln (matching rules) für Projektoren in linearen Räumen

Abstract

Matching rules and composite expansion are useful in asymptotic theory of singular perturbations (method of matched asymptotic expansions, MAE). In this paper we give an algebraic definition of matching rules in abstract vector spaces. We consider the well-known rules from this point of view. By the generality of the definitions we are able to construct new matching rules.