Extendability of functions with partially vanishing trace

Journal Article (2026)
Author(s)

Sebastian BECHTEL (TU Delft - Electrical Engineering, Mathematics and Computer Science)

Russell M. BROWN (University of Kentucky)

Robert HALLER (Technische Universität Darmstadt)

Patrick TOLKSDORF (Karlsruhe Institut für Technologie)

Research Group
Analysis
DOI related publication
https://doi.org/10.5802/aif.3707 Final published version
More Info
expand_more
Publication Year
2026
Language
English
Research Group
Analysis
Journal title
Annales de l'Institut Fourier
Issue number
1
Volume number
76
Pages (from-to)
291-339
Downloads counter
16
Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Abstract

Let Ω ⊆ Rd be open and D ⊆ ∂Ω be a closed part of its boundary. Under very mild assumptions on Ω, we construct a bounded Sobolev extension operator for the Sobolev space WD k,p(Ω), 1 ⩽ p < ∞, which consists of all functions in Wk,p(Ω) that vanish in a suitable sense on D. In contrast to earlier work, this construction is global and does not use a localization argument, which allows to work with a boundary regularity that is sharp at the interface dividing D and ∂Ω \ D. Moreover, we provide homogeneous and local estimates for the extension operator. Also, we treat the case of Lipschitz function spaces with a vanishing trace condition on D.