Tel Aviv University Hello everyone, The next colloquium is part of the Sackler Distinguished Lectures of 2012-2013, and will be held on: Monday, 20/5/2013, 12:15, Schreiber 006, Tel Aviv University. Speaker: Charles L. Fefferman (Princeton University) Title: Extension and interpolation problems I The second talk of the Sackler lectures series (by the same speaker) will be held on: Tuesday, 21/5/2013, 15:10-16:10, at Schreiber 309. Title: Extension and interpolation problems II The abstract is given below. Light refreshments will be served outside the lecture halls on Monday at 12:00, and on Tuesday at 15:00. Hope to see you there. For information about future colloquia, see <http://www.math.tau.ac.il/~ostrover/colloquium/colloq2012.html> Yours, Yaron ************************************* Abstract: Let X be a Banach space of continuous functions on R^n, and let f:E->R be a function defined on an (arbitrary) given subset E of R^n. How can we tell whether f extends to a function F \in X ? If such an F exists, then how small can we take its norm? What can we say about its derivatives at a given point? Can we take F to depend linearly on f? Suppose E is finite. Can we compute an F as above whose norm has the smallest possible order of magnitude? How many computer operations does it take? The talk explains what we know about these questions for X=C^m(R^n), X=C^m, alpha(R^n) (m-th derivatives in Lip(alpha)) and X=W^m,p(R^n). Some of the main results are joint work with Arie Israel, Kevin Luli, and Bo'az Klartag. --------------------------------------------------------- Technion Math Net-2 (TECHMATH2) Editor: Michael Cwikel <techm@math.technion.ac.il> Announcement from: <ostrover@post.tau.ac.il>