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Diameters in Supercritical Random Graphs Via First Passage Percolation

Published online by Cambridge University Press:  05 October 2010

JIAN DING
Affiliation:
Department of Statistics, UC Berkeley, Berkeley, CA 94720, USA (e-mail: jding@stat.berkeley.edu)
JEONG HAN KIM
Affiliation:
Department of Mathematics, Yonsei University, Seoul 120-749, Korea and National Institute for Mathematical Sciences, Daejeon 305-340, Korea (e-mail: jehkim@yonsei.ac.kr)
EYAL LUBETZKY
Affiliation:
Microsoft Research, One Microsoft Way, Redmond, WA 98052-6399, USA (e-mail: eyal@microsoft.com, peres@microsoft.com)
YUVAL PERES
Affiliation:
Microsoft Research, One Microsoft Way, Redmond, WA 98052-6399, USA (e-mail: eyal@microsoft.com, peres@microsoft.com)

Abstract

We study the diameter of 1, the largest component of the Erdős–Rényi random graph (n, p) in the emerging supercritical phase, i.e., for p = where ε3n → ∞ and ε = o(1). This parameter was extensively studied for fixed ε > 0, yet results for ε = o(1) outside the critical window were only obtained very recently. Prior to this work, Riordan and Wormald gave precise estimates on the diameter; however, these did not cover the entire supercritical regime (namely, when ε3n → ∞ arbitrarily slowly). Łuczak and Seierstad estimated its order throughout this regime, yet their upper and lower bounds differed by a factor of .

We show that throughout the emerging supercritical phase, i.e., for any ε = o(1) with ε3n → ∞, the diameter of 1 is with high probability asymptotic to D(ε, n) = (3/ε)log(ε3n). This constitutes the first proof of the asymptotics of the diameter valid throughout this phase. The proof relies on a recent structure result for the supercritical giant component, which reduces the problem of estimating distances between its vertices to the study of passage times in first-passage percolation. The main advantage of our method is its flexibility. It also implies that in the emerging supercritical phase the diameter of the 2-core of 1 is w.h.p. asymptotic to , and the maximal distance in 1 between any pair of kernel vertices is w.h.p. asymptotic to .

Type
Paper
Copyright
Copyright © Cambridge University Press 2010

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References

[1]Addario-Berry, L., Broutin, N. and Goldschmidt, C. (2009) The continuum limit of critical random graphs. Available at: http://arxiv.org/abs/0903.4730.Google Scholar
[2]Alon, N. and Spencer, J. H. (2008) The Probabilistic Method, 3rd edn, Wiley-Interscience Series in Discrete Mathematics and Optimization.CrossRefGoogle Scholar
[3]Bandelt, H.-J. and Chepoi, V. (2008) Metric graph theory and geometry: A survey. In Surveys on Discrete and Computational Geometry, Vol. 453 of Contemporary Mathematics, AMS, Providence, RI, pp. 49–86.Google Scholar
[4]Bhamidi, S., van der Hofstad, R. and Hooghiemstra, G. (2010) First passage percolation on random graphs with finite mean degrees. Ann. Appl. Probab. 20 19071965.CrossRefGoogle Scholar
[5]Bollobás, B. (1980) A probabilistic proof of an asymptotic formula for the number of labelled regular graphs. Europ. J. Combin. 1 311316.Google Scholar
[6]Bollobás, B. (2001) Random Graphs, 2nd edn, Vol. 73 of Cambridge Studies in Advanced Mathematics, Cambridge University Press.Google Scholar
[7]Bollobás, B. (1984) The evolution of random graphs. Trans. Amer. Math. Soc. 286 257274.Google Scholar
[8]Bollobás, B., Janson, S. and Riordan, O. (2007) The phase transition in inhomogeneous random graphs. Random Struct. Alg. 31 3122.CrossRefGoogle Scholar
[9]Chung, F. and Lu, L. (2001) The diameter of sparse random graphs. Adv. Appl. Math. 26 257279.Google Scholar
[10]Ding, J., Kim, J. H., Lubetzky, E. and Peres, Y. Anatomy of a young giant component in the random graph. Random Struct. Alg., in press. Available at: http://arxiv.org/abs/0906.1839.Google Scholar
[11]Erdős, P. and Rényi, A. (1959) On random graphs I. Publ. Math. Debrecen 6 290297.Google Scholar
[12]Fernholz, D. and Ramachandran, V. (2007) The diameter of sparse random graphs. Random Struct. Alg. 31 482516.Google Scholar
[13]Janson, S., Łuczak, T. and Rucinski, A. (2000) Random Graphs, Wiley-Interscience Series in Discrete Mathematics and Optimization.CrossRefGoogle Scholar
[14]Kesten, H. (1986) Aspects of first passage percolation. In École d'Été de Probabilités de Saint-Flour, XIV, 1984, Vol. 1180 of Lecture Notes in Mathematics, Springer, pp. 125264.CrossRefGoogle Scholar
[15]Łuczak, T. (1990) Component behavior near the critical point of the random graph process. Random Struct. Alg. 1 287310.CrossRefGoogle Scholar
[16]Łuczak, T. (1998) Random trees and random graphs. Random Struct. Alg. (Proc. Eighth International Conference ‘Random Structures and Algorithms’, Poznan 1997) 13 485500.3.0.CO;2-Y>CrossRefGoogle Scholar
[17]Łuczak, T. and Seierstad, T. G. The diameter behavior in the random graph process. Preprint.Google Scholar
[18]Lyons, Russell (1992) Random walks, capacity and percolation on trees. Ann. Probab. 20 20432088.Google Scholar
[19]Nachmias, A. and Peres, Y. (2008) Critical random graphs: Diameter and mixing time. Ann. Probab. 36 12671286.Google Scholar
[20]Peres, Y. (1997) Probability on trees: An introductory climb. In Lectures on Probability Theory and Statistics (Saint-Flour), Vol. 1717 of Lecture Notes in Mathematics, Springer, pp. 193280.Google Scholar
[21]Riordan, O. and Wormald, N. C. (2008) The diameter of sparse random graphs. Preprint, available at: http://arxiv.org/abs/0808.4067v1.Google Scholar
[22]Riordan, O. and Wormald, N. C. (2009) The diameter of sparse random graphs. To appear, available at: http://arxiv.org/abs/0808.4067v2.Google Scholar
[23]Wormald, N. C. (1999) Models of random regular graphs. In Surveys in Combinatorics 1999, Vol. 267 of London Mathematical Society Lecture Notes, Cambridge University Press, pp. 239298.Google Scholar