This talk gave a sketch of the contents and background to a book with the titleNonabelian
algebraic topology'being written under support of a Leverhulme Emeritus Fellowship (2002 …

On the Asphericity of Length Four Relative Group Presentations. Sign In Folder Preferences
Languages New Features! Help Exit New Search Publications Subject Terms Cited References …

Let χ be a property pertaining to subgroups. Several authors have studied the structure of
groups" many" of whose subgroups have the property χ. In particular, dealing with infinite …

Let p be a prime or 0. A presentation P (defining a group G) is said to be p-Cockcroft if the
map π2 (P)→ H2 (P, Zp) is 0 (where Z0= Z). Moreover, if H is a subgroup of G then P is pH …

Consider any group G. A [G, 2]-complex is a connected 2-dimensional CW-complex with
fundamental group G. If X is a [G, 2]-complex and L is a subgroup of G, let XL denote the …

Necessary and sufficient conditions are obtained for the 2-skeleton of the total space of a
graph of 2-complexes to be Cockcroft, or L-Cockcroft for some subgroup L of the …

Quillen's plus construction, familiar from algebraic Κ-theory, may be applied to any
topological space relative to a perfect normal subgroup L of the fundamental group G. We …

The idea of applying isoperimetric functions to group theory is due to M. Gromov [8]. We
introduce the concept of a “bicombing of narrow shape” which generalizes the usual notion …

In this note, we use techniques in the topology of 2-complexes to recast some tools that have
arisen in the study of planar tiling questions. With spherical pictures, we show that the tile …

This dissertation explores a relative identity property defined on a pair of two-dimensional
CW-complexes,(Y, X), where Y is obtained from X by adding 2-cells. Such two-complex pairs …