For two kinds of sets X in Rn, we prove the existence of linear continuous operators extending C∞ functions on X to C ∞functions on Rn. The sets we consider are: (a) sequences of points in the real line converging to 0 at a polynomial rate, (b) flag-shaped sets in the plane, which are unions of half-lines with slopes as in (a).
All Science Journal Classification (ASJC) codes
- C-infinity extension
- Fan-shaped sets
- Linear extension operator