W. A. Bogley and A. J. Sieradski, Weighted combinatorial group theory and wild metric complexes, 11 August, 1997

Abstract

In this paper, we develop the low dimensional homotopy theory required for weighted combinatorial group theory. In Omega-groups, an earlier paper by Sieradski, the usual concepts of generators and relators of group presentations are extended to weighted generators and weighted relators for weighted group presentations. This extension parallels the passage from finite sets to order types, i.e. closed nowhere dense sets in the closed unit interval. In the weighted environment, products of all order-type are permitted, provided that the entries of the product have weights that limit at zero as their depth of occurrence in the order-type increases without bound. Here, we develop weighted analogs of the usual correspondence via fundamental groups between free groups and 1-dimensional CW cell complexes and between group presentations and 2-dimensional CW cell complexes. The results are a correspondence between free omega-groups and wild metric 1-complexes in which the 1-cells can limit on 0-cells and a correspondence between weighted group presentations and wild metric 2-complexes in which the 1-cells and 2-cells can limit on the 0-cells.