| Abstract: In
this work, for a local number field or a global number field, we derive
the central simple algebras
characterization of the Schur index of an absolutely irreducible character of a finite group from the cohomological one. Then we use the cohomological characterization of the Schur index to give new unified proofs of the theorems of Roquette, Ford, Solomon, and Fong which were obtained by separate methods. |