The main result is that for every recursively enumerable existential consistent theory Γ (in the usual language of group theory), there exists a finitely presented SQ-universal group H such that Γ is satisfied in every nontrivial quotient of H. Furthermore if Γ is satisfied in some group with soluble word problem, then one can take H with soluble word problem. We characterize the finitely gener...

In 1954 A. G. Howson proved that the intersection of two finitely generated subgroups of a free group is again finitely generated. Now the free metabelian subgroups of a free metabelian group of finite rank n are quite restricted. Indeed they are again of finite rank at most n. This suggests that there may be an analog of Howson’s theorem for free metabelian groups. This turns out not to be the...

Two groups are said to have the same nilpotent genus if they have the same nilpotent quotients. We answer four questions of Baumslag concerning nilpotent completions. (i) There exists a pair of finitely generated, residually torsion-free-nilpotent groups of the same nilpotent genus such that one is finitely presented and the other is not. (ii) There exists a pair of finitely presented, residual...

Let $(R, m)$ be a commutative noetherian local ring and let $Gamma$ be a finite group. It is proved that if $R$ admits a dualizing module, then the group ring $Rga$ has a dualizing bimodule as well. Moreover, it is shown that a finitely generated $Rga$-module $M$ has generalized Gorenstein dimension zero if and only if it has generalized Gorenstein dimension zero as an $R$-module.

This paper provides a thorough explication of the Structure Theorem for Abelian groups and of the background information necessary to prove it. The outline of this paper is as follows. We first consider some theorems related to abelian groups and to R-modules. In this section we see that every finitely generated abelian group is the epimorphic image of a finitely generated free abelian group. H...

‎By the Mordell‎- ‎Weil theorem‎, ‎the group of rational points on an elliptic curve over a number field is a finitely generated abelian group‎. ‎This paper studies the rank of the family Epq:y2=x3-pqx of elliptic curves‎, ‎where p and q are distinct primes‎. ‎We give infinite families of elliptic curves of the form y2=x3-pqx with rank two‎, ‎three and four‎, ‎assuming a conjecture of Schinzel ...

We prove that any finitely generated solvable group of zero entropy contains a nilpotent subgroup of finite index. In particular, any finitely generated solvable group of exponential growth is of uniformly exponential growth.

A group G given by a presentation G = 〈A ‖ R〉 is called weakly finitely presented if every finitely generated subgroup of G, generated by (images of) some words in A, is naturally isomorphic to the subgroup of a group G0 = 〈A0 ‖ R0〉, where A0 ⊆ A, R0 ⊆ R are finite, generated by (images of) the same words. In the article, weakly finitely presented periodic groups which are not locally finite ar...