49 citations · 164 across the 34 of their papers we have counts for
5 papers · 1 filter
Triangles, squares and geodesics
Rena Levitt, Jon McCammond
In the early 1990s Steve Gersten and Hamish Short proved that compact nonpositively curved triangle complexes have biautomatic fundamental groups and that compact nonpositively cur…
Braids, posets and orthoschemes
Tom Brady, Jon McCammond
In this article we study the curvature properties of the order complex of a graded poset under a metric that we call the ``orthoscheme metric''. In addition to other results, we ch…
Combinatorial descriptions of multi-vertex 2-complexes
Jon McCammond
Group presentations are implicit descriptions of 2-dimensional cell complexes with only one vertex. While such complexes are usually sufficient for topological investigations of gr…
Windmills and extreme 2-cells
Jon McCammond, Daniel Wise
In this article we prove new results about the existence of 2-cells in disc diagrams which are extreme in the sense that they are attached to the rest of the diagram along a small…
The integral cohomology of the group of loops
Craig A Jensen, Jon McCammond, John Meier
Let PSigma_n denote the group that can be thought of either as the group of motions of the trivial n-component link or the group of symmetric automorphisms of a free group of rank…