Finite p-groups with automorphism of a special form

Research on finite solvable groups with C-closed invariant subgroups has given rise to groups structured as follows. Let p, q₁, q₂, ..., q_m be distinct primes, n_i be the exponent of p modulo q_i, and n be the exponent of p modulo . Then G = Pλ〈x〉, where P is a group and ; Z_i; here, Z_i and P/Z(P) are elementary Abelian groups of respective orders and pⁿ, |x| = r, the element x acts irreducibly on P/Z(P) and on each of the subgroups Z_i, and . We state necessary and sufficient conditions for such groups to exist. __________ Translated from Algebra i Logika, Vol. 45, No. 4, pp. 379–389, July–August, 2006.