Stable lifting of polynomial traces on triangles

We construct a right inverse of the trace operator u 7→ (u|∂T , ∂nu|∂T ) on the reference triangle T that maps suitable piecewise polynomial data on ∂T into polynomials of the same degree and is bounded in all Ws,q (T) norms with 1 < q < ∞ and s ≥ 2. The analysis relies on new stability estima...

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Bibliographic Details
Main Authors: Parker, C, Suli, E
Format: Journal article
Language:English
Published: Society for Industrial and Applied Mathematics 2024
Description
Summary:We construct a right inverse of the trace operator u 7→ (u|∂T , ∂nu|∂T ) on the reference triangle T that maps suitable piecewise polynomial data on ∂T into polynomials of the same degree and is bounded in all Ws,q (T) norms with 1 < q < ∞ and s ≥ 2. The analysis relies on new stability estimates for three classes of single edge operators. We then generalize the construction for mth-order normal derivatives, m ∈ N0.