We give a simple construction of new, complete, finite volume manifolds M bounded, nonpositive curvature. These have ends that look like mixture locally symmetric different ranks and their fundamental groups are not duality groups.

We give two applications of the recent classification of locally finite simple finitary skew linear groups. We show that certain irreducible finitary skew linear groups of infinite dimension, generate the variety of all groups and have infinite Prüfer rank.

let g = (v,e) be a locally finite graph, i.e. a graph in which every vertex has finitely many adjacent vertices. in this paper, we associate a topology to g, called graphic topology of g and we show that it is an alexandroff topology, i.e. a topology in which intersec- tion of every family of open sets is open. then we investigate some properties of this topology. our motivation is to give an e...