let $g$ be a non-abelian group of order $p^n$‎, ‎where $nleq 5$ in which $g$ is not extra special of order $p^5$‎. ‎in this paper we determine the maximal size of subsets $x$ of $g$‎ ‎with the property that $xyneq yx$ for any $x,y$ in $x$ with‎ ‎$xneq y$‎.

We generalise Merzlyakov's theorem about the first-order theory of non-abelian free groups to all acylindrically hyperbolic groups. As a corollary, we deduce that if $G$ is an group and $E(G)$ denotes unique maximal finite normal subgroup $G$, then HNN extension $G\dot{\ast}_{E(G)}$, which simply product $G\ast\mathbb{Z}$ when trivial, have same $\forall\exists$-theory. consequence, prove follo...

What ingredients are necessary to describe all maximal subgroups of the general finite group G? This paper is concerned with providing such an analysis. A good first reduction is to take into account the first isomorphism theorem, which tells us that the maximal subgroups containing a given normal subgroup N of G correspond, under the natural projection, to the maximal subgroups of the quotient...

The Pukánszky invariant associates to each maximal abelian self–adjoint subalgebra (masa) A in a type II1 factor M a certain subset ot N ∪ {∞}, denoted Puk(A). We study this invariant in the context of factors generated by infinite conjugacy class discrete countable groups G with masas arising from abelian subgroups H. Our main result is that we are able to describe Puk(V N(H)) in terms of the ...