Let B be a p-block of a finite group, and set m = ∑ χ(1), the sum taken over all height zero characters of B. Motivated by a result of M. Isaacs characterising p-nilpotent finite groups in terms of character degrees, we show that B is nilpotent if and only if the exact power of p dividing m is equal to the p-part of |G : P ||P : R|, where P is a defect group of B and where R is the focal subgro...

Let G and E stand for one of the following pairs of groups: • Either G is the general quadratic group U(2n, R,Λ), n ≥ 3, and E its elementary subgroup EU(2n, R,Λ), for an almost commutative form ring (R,Λ), • or G is the Chevalley group G(Φ, R) of type Φ, and E its elementary subgroup E(Φ, R), where Φ is a reduced irreducible root system of rank ≥ 2 and R is commutative. Using Bak’s localizatio...

By the Shepherd–Leedham-Green–McKay theorem on finite p-groups of maximal class, if a finite p-group of order pn has nilpotency class n−1, then it has a subgroup of nilpotency class at most 2 with index bounded in terms of p. Counterexamples to a rank analogue of this theorem are constructed, which give a negative solution to Problem 16.103 in Kourovka Notebook. Moreover, it is shown that there...

Baumslag conjectured in the 1970s that the automorphism tower of a finitely generated free group (free nilpotent group) must be very short. Dyer and Formanek [9] justified the conjecture concerning finitely generated free groups in the “sharpest sense” by proving that the automorphism group Aut(Fn) of a non-abelian free group Fn of finite rank n is complete. Recall that a group G is said to be ...

let h be a subgroup of a group g. h is said to be s-embedded in g if g has a normal t such that ht is an s-permutable subgroup of g and h ∩ t ≤ h sg, where h denotes the subgroup generated by all those subgroups of h which are s-permutable in g. in this paper, we investigate the influence of minimal s-embedded subgroups on the structure of finite groups. we determine the structure the finite grou...

We develop a unifying approach to study projectivity and unification in substructural logics corresponding varieties of residuated lattices generated by generalized rotation constructions. These include many interesting especially the realm mathematical fuzzy logics. Our main results pertain what we shall call radical-determined rotations, which all most relevant this framework. characterize fr...

Conditions are given for a class 2 nilpotent group to have no central extensions of class 3. This is related to Betti numbers and to the problem of representing a class 2 nilpotent group as the fundamental group of a smooth projective variety. Surveys of the work on the characterization of the fundamental groups of smooth projective varieties and Kähler manifolds (see [1],[3], [9]) indicate tha...

For $G$ a finite group, let $d_2(G)$ denote the proportion of triples $(x, y, z) \in G^3$ such that $[x, z] = 1$. We determine structure groups is bounded away from zero: if $d_2(G) \geq \epsilon > 0$, has class-4 nilpotent normal subgroup $H$ $[G : H] $ and $|\gamma_4(H)|$ are both in terms $\epsilon$. also show an infinite group whose commutators have boundedly many conjugates, or indeed sati...

We prove that the theory of the p-adics Qp, together with a set of explicitly given sorts, admits elimination of imaginaries. Using p-adic integration, we deduce the rationality of certain formal zeta functions arising from definable equivalence relations. As an application, we prove rationality results for zeta functions obtained by counting isomorphism classes of irreducible representations o...