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SUMMARY:Geometric Selection Theorems - Boris Bukh (UCLA)
DTSTART:20090123T163000Z
DTEND:20090123T173000Z
UID:TALK16171@talks.cam.ac.uk
CONTACT:Ben Green
DESCRIPTION:In combinatorial geometry one frequently wants to\nselect a po
 int or a set of points that meets many simplices of a given\nfamily. The t
 wo examples are choosing a point in many simplices\nspanned by points of s
 ome P in R^d\, and choosing a small set of points\nwhich meets the convex 
 hull of every large subset of P (the weak\nepsilon-net problem). I will pr
 esent a new class of constructions that\nyield the first nontrivial lower 
 bound on the weak epsilon-net\nproblem\, and improve the best bounds for s
 everal other selection\nproblems. Joint work with Jiri Matousek and Gabrie
 l Nivasch.
LOCATION:MR13\, CMS
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