## The lifting of polynomial traces revisited

*Christine Bernardi,
Monique Dauge
and
Yvon Maday
*
* *

We construct a lifting operator of polynomial traces on an interval that is stable in appropriate Sobolev norms. Next we extend this result to the case of traces vanishing at the endpoints of the interval.
This has two applications, the interpolation of polynomial spaces and the evaluation by discrete formulas of fractional order Sobolev norms on polynomials.
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* Preprint IRMAR ***08-08**,

Preprint Laboratoire Jacques-Louis Lions **R08007**.

Paris, Rennes, January 2008

*Math. Comp.* ** 79** (269), Jan 2010, pages 47-69.