Two typos (arXiv version, v2)
1. Eq.(1), r_H should be r_h (thanks Hal Daume for pointing this out).
2. pg 33, Lemma 11 proof: the RHS of the equation on the bottom of the page should have alpha in the place of kappa. The rest of the proof holds because this expression is monotonically decreasing as alpha increases (thanks Bochao Li (UIUC) for pointing this out).