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A Limit Law of Almost l-partite Graphs

Published online by Cambridge University Press:  12 March 2014

Vera Koponen*
Affiliation:
Department of Mathematics, Uppsala University, Box 480, 75106 Uppsala, Sweden, E-mail: [email protected]

Abstract

For integers l ≥ 1, d ≥ 0 we study (undirected) graphs with vertices 1, …, n such that the vertices can be partitioned into l parts such that every vertex has at most d neighbours in its own part. The set of all such graphs is denoted Pn (l, d). We prove a labelled first-order limit law, i.e., for every first-order sentence φ, the proportion of graphs in Pn (l, d) that satisfy φ converges as n → ∞. By combining this result with a result of Hundack, Prömel and Steger [12] we also prove that if 1 ≤ s1 ≤ … ≤ sl are integers, then Forb() has a labelled first-order limit law, where Forb() denotes the set of all graphs with vertices 1, …, n, for some n, in which there is no subgraph isomorphic to the complete (l + 1 )-partite graph with parts of sizes 1, s1, …, sl. In the course of doing this we also prove that there exists a first-order formula ξ, depending only on l and d, such that the proportion of Pn (l, d) with the following property approaches 1 as n → ∞: there is a unique partition of {1, …, n} into l parts such that every vertex has at most d neighbours in its own part, and this partition, viewed as an equivalence relation, is defined by ξ.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2013

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References

REFERENCES

[1] Balogh, J., Bollobás, B., and Simonovits, M., The typical structure of graphs without given excluded subgraphs, Random Structures and Algorithms, vol. 34 (2009), pp. 305318.CrossRefGoogle Scholar
[2] Balogh, J., Bollobás, B., and Simonovits, M., The fine structure of octahedron-free graphs, Journal of Combinatorial Theory, Series B, vol. 101 (2011), pp. 6784.Google Scholar
[3] Burris, S. N., Number theoretic density and logical limit laws, Mathematical Surveys and Monographs, vol. 86, American Mathematical Society, 2001.Google Scholar
[4] Compton, K. J., A logical approach to asymptotic combinatorics. I. First order properties, Advances in Mathematics, vol. 65 (1987), pp. 6596.Google Scholar
[5] Compton, K. J., The computational complexity of asymptotic problems I: Partial orders, Information and Computation, vol. 78 (1988), pp. 108123.CrossRefGoogle Scholar
[6] Diestel, R., Graph theory, third ed., Springer, 2005.Google Scholar
[7] Ebbinghaus, H-D. and Flum, J., Finite model theory, second ed., Springer-Verlag, 1999.Google Scholar
[8] Erdős, P., Kleitman, D. J., and Rothschild, B. L., Asymptotic enumeration of Kn-free graphs, International Colloquium on Combinatorial Theory, vol. 2, Atti dei Convegni Lincei, no. 17, Rome, 1976, pp. 1927.Google Scholar
[9] Fagin, R., Probabilities on finite models, this Journal, vol. 41 (1976), pp. 5058.Google Scholar
[10] Glebskii, Y. V., Kogan, D. I., Liogonkii, M. I., and Talanov, V. A., Volume and fraction of satisfiability of formulas of the lower predicate calculus, Kibernetyka, vol. 2 (1969), pp. 1727.Google Scholar
[11] Haber, S. and Krivelevich, M., The logic of random regular graphs, Journal of Combinatorics, vol. 1 (2010), pp. 389440.Google Scholar
[12] Hundack, C., Prömel, H. J., and Steger, A., Extremal graph problems for graphs with a color-critical vertex, Combinatorics, Probability and Computing, vol. 2 (1993), pp. 465477.Google Scholar
[13] Kolaitis, Ph. G., Prömel, H. J., and Rothschild, B. L., Kl+1-free graphs: asymptotic structure and a 0-1 law, Transactions of the American Mathematical Society, vol. 303 (1987), pp. 637671.Google Scholar
[14] Koponen, V., Asymptotic probabilities of extension properties andrandom l-colourable structures, Annals of Pure and Applied Logic, vol. 163 (2012), pp. 391438.Google Scholar
[15] Koponen, V., Random graphs with bounded maximum degree: asymptotic structure and a logical limit law, Discrete Mathematics and Theoretical Computer Science, vol. 14 (2012), pp. 229254.Google Scholar
[16] Lynch, J. F., Convergence law for random graphs with specified degree sequence, ACM Transactions on Computational Logic, vol. 6 (2005), pp. 727748.CrossRefGoogle Scholar
[17] Prömel, H. J. and Steger, A., The asymptotic number of graphs not containing a fixed color critical subgraph, Combinatorica, vol. 12 (1992), pp. 463473.Google Scholar
[18] Shelah, S. and Spencer, J., Zero-one laws for sparse random graphs, Journal of the American Mathematical Society, vol. 1 (1988), pp. 97115.Google Scholar
[19] Spencer, J., The strange logic of random graphs, Algorithms and Combinatorics, vol. 22, Springer-Verlag, 2001.Google Scholar