Extendability of functions with partially vanishing trace
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)
More Info
expand_more
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.