Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6424339 | European Journal of Combinatorics | 2013 | 4 Pages |
Abstract
Let AâR be a finite set and let K⩾1 be a real number. Suppose that for each aâA we are given an injective map Ïa:AâR which fixes a and contracts other points towards it in the sense that |aâÏa(x)|⩽1K|aâx| for all xâA, and such that Ïa(x) always lies between a and x. Then |âaâAÏa(A)|⩾K10|A|âOK(1). An immediate consequence of this is the estimate |A+Kâ A|⩾K10|A|âOK(1), which is a slightly weakened version of a result of Bukh.
Related Topics
Physical Sciences and Engineering
Mathematics
Discrete Mathematics and Combinatorics
Authors
Emmanuel Breuillard, Ben Green,