Whitney ’ s Extension Problems and Interpolation of Data

@inproceedings{Fefferman2008WhitneyS,
  title={Whitney ’ s Extension Problems and Interpolation of Data},
  author={Charles Fefferman},
  year={2008}
}
Given a function f : E → R with E ⊂ Rn, we explain how to decide whether f extends to a Cm function F on Rn. If E is finite, then one can efficiently compute an F as above, whose Cm norm has the least possible order of magnitude (joint work with B. Klartag).