Translation invariant projections in Sobolev spaces on tori in the L¹ and uniform norms
Volume 100 / 1991
Studia Mathematica 100 (1991), 149-167
DOI: 10.4064/sm-100-2-149-167
Abstract
The idempotent multipliers on Sobolev spaces on the torus in the L¹ and uniform norms are characterized in terms of the coset ring of the dual group of the torus. This result is deduced from a more general theorem concerning certain translation invariant subspaces of vector-valued function spaces on tori.