The adjunction problem over torsion-free groups
arXiv:math/0412274 · doi:10.1073/pnas.0502940102
Abstract
In this note we prove injectivity and relative asphericity for "layered" systems of equations over torsion-free groups, when the exponent matrix is invertible over Z. We also give elementary geometric proofs of results due to Bogley-Pride and Serre that are used in the proof of the main theorem.
7 pages, hyperlinked latex. Version 2: proof of Serre's theorem added