Interpolation of Hilbert and Sobolev spaces: quantitative estimates and counterexamples

Chandler-Wilde, S. N. ORCID: https://orcid.org/0000-0003-0578-1283, Hewett, D. P. and Moiola, A. (2015) Interpolation of Hilbert and Sobolev spaces: quantitative estimates and counterexamples. Mathematika, 61 (2). pp. 414-443. ISSN 0025-5793 doi: 10.1112/S0025579314000278

Abstract/Summary

This paper provides an overview of interpolation of Banach and Hilbert spaces, with a focus on establishing when equivalence of norms is in fact equality of norms in the key results of the theory. (In brief, our conclusion for the Hilbert space case is that, with the right normalisations, all the key results hold with equality of norms.) In the final section we apply the Hilbert space results to the Sobolev spaces Hs(Ω) and tildeHs(Ω), for s in R and an open Ω in R^n. We exhibit examples in one and two dimensions of sets Ω for which these scales of Sobolev spaces are not interpolation scales. In the cases when they are interpolation scales (in particular, if Ω is Lipschitz) we exhibit examples that show that, in general, the interpolation norm does not coincide with the intrinsic Sobolev norm and, in fact, the ratio of these two norms can be arbitrarily large.

Additional Information	Please see the corrigendum of this article https://doi.org/10.1112/mtk.12155, published 11/10/2022.
Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/37632
Identification Number/DOI	10.1112/S0025579314000278
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Mathematics and Statistics
Additional Information	Please see the corrigendum of this article https://doi.org/10.1112/mtk.12155, published 11/10/2022.
Publisher	London Mathematical Society
Download/View statistics	View download statistics for this item