Universal Extension Operator
Lev Kapitanski · Functional Analysis and Its Applications · 2025
Abstract A new linear extension operator which extends (generalized) functions on a hyperplane in a Euclidean space to the whole space is introduced. It is shown that this operator is continuous as an operator between appropriate function spaces for a large class of Sobolev–Slobodetsky, Besov, and Triebel–Lizorkin spaces.