Sharp L^p estimates on BMO
arXiv:1110.1771
Abstract
We construct the upper and lower Bellman functions for the (quasi)-norms of BMO functions. These appear as solutions to a series of Monge--Ampère boundary value problems on a non-convex plane domain. The knowledge of the Bellman functions leads to sharp constants in inequalities relating average oscillations of BMO functions and various BMO norms.
42 pages, 12 figures