Abstract Let G be a finitely generated group that can written as an extension $$ \begin{align*} 1 \longrightarrow K \stackrel{i}{\longrightarrow} \stackrel{f}{\longrightarrow} \Gamma \end{align*} where is group. By study of the Bieri–Neumann–Strebel (BNS) invariants we prove if $b_1(G)> b_1(\Gamma ) > 0$ , then algebraically fibres; is, admits epimorphism to $\Bbb {Z}$ with kernel. An int...

This paper studies the vanishing of $Ext$ modules over group rings. Let $R$ be a commutative noetherian ring and $ga$ a group. We provide a criterion under which the vanishing of self extensions of a finitely generated $Rga$-module $M$ forces it to be projective. Using this result, it is shown that $Rga$ satisfies the Auslander-Reiten conjecture, whenever $R$ has finite global dimension and $ga...

This document specifies an Extensible Authentication Protocol (EAP) mechanism for authentication and session key distribution using the GSM Subscriber Identity Module (SIM). Haverinen Expires in six months [Page 1] Internet Draft EAP SIM Authentication November 2001

Let F be a differential field of characteristic zero with algebraically closed field of constants. We provide an explicit description of the twisted Lie algebras of PGL3-equivariant derivations on the coordinate rings of F -irreducible PGL3-torsors in terms of nine-dimensional central simple algebras over F . We use this to construct a Picard–Vessiot extension which is the function field of a n...