The Gap between the Schur Group and the Subgroup Generated by Cyclic Cyclotomic Algebras
نویسندگان
چکیده
Let K be an abelian extension of the rationals. Let S(K) be the Schur group of K and let CC(K) be the subgroup of S(K) generated by classes containing cyclic cyclotomic algebras. We characterize when CC(K) has finite index in S(K) in terms of the relative position of K in the lattice of cyclotomic extensions of the rationals.
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