Let be the space of functions on whose derivatives have modulus of continuity . For , let be the space of all restrictions to of functions in . We show that there exists a bounded linear operator such that, for any , we have on .
Cite this article
Charles Fefferman, Extension of -Smooth Functions by Linear Operators. Rev. Mat. Iberoam. 25 (2009), no. 1, pp. 1–48