#28 Representations of rational Cherednik algebras of G(m,r,n) in positive characteristic In Proposition 4.7, there should be t^p in place of t in the polynomial K'. The corrected line should read [Q] \sum_{\underline{\mu}} K'_{\underline{\mu}, \underline{\lambda}}(t^p) [S_{\underline{\mu}}] #18 GL-equivariant modules over polynomial rings in infinitely many variables v3: Part of the explanation in Remark 4.3.3 was corrected. #6 Pieri resolutions for classical groups v4: * Theorem 3.6 originally stated that the mapping cone construction produces a minimal free resolution. The proof ignored the fact that in the horizontal differentials, one could have H^0 terms mapping to H^1 terms which would give non-minimality. One can avoid this situation by assuming that the original resolution has no linear differentials. The proof in each case has been updated to take this assumption into account. * The reasoning in the first paragraph of Section 4.2 about why non-free equivariant modules must have finite length was stated incorrectly, but only slightly so, and it has been corrected. v5: * This version correctly attributes certain results to Peter Olver. See the section "New in this version" at the end of the introduction.