Abstract
A labeled oriented tree is called injective, if each vertex occurs at most once as an edge label. We show that injective labeled oriented trees are aspherical. The proof uses a new relative asphericity test based on a lemma of Stallings.
Similar content being viewed by others
Notes
We thank Manuela Ana Cerdeiro for pointing this example out to us.
References
Bogley, W.A.: J.H.C. Whitehead’s asphericity question. In: Hog-Angeloni, C., Metzler, W., Sieradski, A.J. (eds.) Two-dimensional Homotopy and Combinatorial Group Theory. LMS Lecture Note Series 197, CUP (1993)
Bogley, W.A., Pride, S.J.: Calculating generators of \(\pi _2\). In: Hog-Angeloni, C., Metzler, W., Sieradski, A.J. (eds.) Two-dimensional Homotopy and Combinatorial Group Theory. LMS Lecture Note Series 197, CUP (1993)
Gersten, S.M.: Reducible diagrams and equations over groups. In: Gersten editor, S.M. (ed.) Essays in Group Theory, Mathematical Sciences Research Institute Publications. Springer, New York, pp. 15–73
Gersten, S.M.: Branched coverings of 2-complexes and diagrammatic reducibility. Trans. AMS 303(2), 689–706 (1987)
Harlander, J., Rosebrock, S.: Generalized knot complements and some aspherical ribbon disc complements. J. Knot Theory Ramif. 12(7), 947–962 (2003)
Howie, J.: Some remarks on a problem of J.H.C. Whitehead. Topology 22, 475–485 (1983)
Howie, J.: On the asphericity of ribbon disc complements. Trans. AMS 289(1), 281–302 (1985)
Huck, G., Rosebrock, S.: Weight tests and hyperbolic groups. In: Duncan, A., Gilbert, N., Howie, J. (eds.) Combinatorial and Geometric Group Theory; Edinburgh 1993; Cambridge University Press; London Mathematical Society Lecture Notes Series 204, pp. 174–183 (1995)
Huck, G., Rosebrock, S.: Aspherical labeled oriented trees and knots. Proc. Edinb. Math. Soc. 44, 285–294 (2001)
Kauffman, L.H.: Virtual knot theory. Eur. J. Comb. 20, 663–691 (1999)
Rosebrock, S.: The Whitehead conjecture—an overview. Sib. Electron. Math. Rep. 4, 440–449 (2007)
Stallings, J.: A graph-theoretic lemma and group-embeddings. In: Gersten, J.R., Stallings, S.M. (eds.) Proceedings of the Alta Lodge 1984, Annals of Mathematical Studies, Princeton University Press, pp. 145–155 (1987)
Whitehead, J.H.C.: On the asphericity of regions in a 3-sphere. Fund. Math. 32, 149–166 (1939)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Harlander, J., Rosebrock, S. Injective labeled oriented trees are aspherical. Math. Z. 287, 199–214 (2017). https://doi.org/10.1007/s00209-016-1823-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00209-016-1823-6