Abstract
We study relations between geometric embeddings of graphs and the spectrum of associated matrices, focusing on outerplanar embeddings of graphs. For a simple connected graph G = (V, E), we define a “good” G-matrix as a V × V matrix with negative entries corresponding to adjacent nodes, zero entries corresponding to distinct nonadjacent nodes, and exactly one negative eigenvalue. We give an algorithmic proof of the fact that if G is a 2-connected graph, then either the nullspace representation defined by any “good” G-matrix with corank 2 is an outerplanar embedding of G, or else there exists a “good” G-matrix with corank 3.
Dedicated to the memory of Jiří Matoušek
The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement no. 227701.
The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement no. 339109.
References
Y. Colin de Verdière, Sur un nouvel invariant des graphes et un critère de planarité. J. Combin. Theory Ser. B 50, 11–21 (1990) [English transl.: On a new graph invariant and a criterion for planarity, in: Graph Structure Theory, ed. by N. Robertson, P. Seymour (American Mathematical Society, Providence, 1993), pp. 137–147]
R. Connelly, Rigidity and energy. Invent. Math. 66, 11–33 (1982)
M. Laurent, A. Varvitsiotis, Positive semidefinite matrix completion, universal rigidity and the Strong Arnold Property. Linear Algebra Appl. 452, 292–317 (2014)
L. Lovász, Steinitz representations and the Colin de Verdière number. J. Combin. Theory B 82, 223–236 (2001)
L. Lovász, A. Schrijver, A Borsuk theorem for antipodal links and a spectral characterization of linklessly embeddable graphs. Proc. Am. Math. Soc. 126, 1275–1285 (1998)
L. Lovász, A. Schrijver, On the null space of a Colin de Verdière matrix. Annales de l’Institut Fourier, Université de Grenoble 49, 1017–1026 (1999)
N. Robertson, P. Seymour, R. Thomas, Sachs’ linkless embedding conjecture. J. Combin. Theory Ser. B 64, 185–227 (1995)
A. Schrijver, B. Sevenster, The Strong Arnold Property for 4-connected flat graphs. Linear Algebra Appl. 522, 153–160 (2017)
H. van der Holst, A short proof of the planarity characterization of Colin de Verdière. J. Combin. Theory Ser. B 65, 269–272 (1995)
H. van der Holst, Topological and spectral graph characterizations. Ph.D. thesis, University of Amsterdam, Amsterdam (1996)
H. van der Holst, L. Lovász, A. Schrijver, The Colin de Verdière graph parameter, in Graph Theory and Combinatorial Biology. Bolyai Society Mathematical Studies, vol. 7 (János Bolyai Mathematical Society, Budapest, 1999), pp. 29–85
Acknowledgements
We thank Bart Sevenster for helpful discussion on κ(G), and two referees for useful suggestions improving the presentation.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2017 Springer International publishing AG
About this chapter
Cite this chapter
Lovász, L., Schrijver, A. (2017). Nullspace Embeddings for Outerplanar Graphs. In: Loebl, M., Nešetřil, J., Thomas, R. (eds) A Journey Through Discrete Mathematics. Springer, Cham. https://doi.org/10.1007/978-3-319-44479-6_23
Download citation
DOI: https://doi.org/10.1007/978-3-319-44479-6_23
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-44478-9
Online ISBN: 978-3-319-44479-6
eBook Packages: Mathematics and StatisticsMathematics and Statistics (R0)