%0 PDF %T Blocks and F-class algebras of finite groups. %A Reynolds, William F. %D 2018-07-19T09:44:23.953-04:00 %8 2018-07-19 %I Tufts University. Tisch Library. %R http://localhost/files/7d2795676 %X For an arbitrary field F of characteristic p ≧ 0, the usual partitioning of the p-regular elements of a finite group G into F-classes (F-conjugacy classes) is extended to all of G in such a way that the F-classes form a basis of a subalgebra Y of the class algebra Z of G over F. The primitive idempotents of E ⊗FY , where E is an algebraic closure of F, are the same as those of Z. By means of this fact it is shown that if p > 0 the number of blocks of G over F with a given defect group D is not greater than the number of p-regular F-classes L of G with defect group D such that the F-class sum of L in Z is not nilpotent; equality holds if Op,p′,p(G) = G or if D is Sylow in G. The results are generalized to arbitrary twisted group algebras of G over F. %[ 2018-10-10 %9 Text %~ Tufts Digital Library %W Institution