On the automorphism group of Solomon's descent algebra.
Let G be a finite p-group and let F be the field of p elements. It is shown that if G is elementary abelian-by-cyclic then the isomorphism type of G is determined by FG.
All commutative semigroups are described such that the Jacobson radical is homogeneous in each ring graded by .
Let be a finite nonabelian group, its associated integral group ring, and its augmentation ideal. For the semidihedral group and another nonabelian 2-group the problem of their augmentation ideals and quotient groups is deal with. An explicit basis for the augmentation ideal is obtained, so that the structure of its quotient groups can be determined.
We give the characterization of the unit group of , where is a finite field with elements for prime and denotes the special linear group of matrices having determinant over the cyclic group .