Isomorphism problem of Unitary Subgroups of Group Algebras

Abstract: Let V_* be the normalized unitary subgroup of the modular group algebra FG of a finite p-group G over a finite field F with the classical involution . We investigate the isomorphism problem for the group V_, that asks when the group V_* is determined by its group algebra FG. We confirm it for classes of finite abelian p-groups, 2-groups of maximal class and non-abelian 2-groups of order at most 16.