Distances in random graphs with finite variance degrees

  • Authors:
  • Remco van der Hofstad;Gerard Hooghiemstra;Piet Van Mieghem

  • Affiliations:
  • Department of Mathematics and Computer Science, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands;Delft University of Technology, Electrical Engineering, Mathematics and Computer Science, P.O. Box 5031, 2600 GA Delft, The Netherlands;Delft University of Technology, Electrical Engineering, Mathematics and Computer Science, P.O. Box 5031, 2600 GA Delft, The Netherlands

  • Venue:
  • Random Structures & Algorithms
  • Year:
  • 2005

Quantified Score

Hi-index 0.00

Visualization

Abstract

In this paper we study a random graph with N nodes, where node j has degree Dj and {Dj} j=1N are i.i.d. with ℙ(Dj ≤ x) = F(x). We assume that 1 - F(x) ≤ cx-&tgr;+1 for some &tgr; 3 and some constant c 0. This graph model is a variant of the so-called configuration model, and includes heavy tail degrees with finite variance. The minimal number of edges between two arbitrary connected nodes, also known as the graph distance or the hopcount, is investigated when N → ∞. We prove that the graph distance grows like log&ngr; N, when the base of the logarithm equals &ngr; = 𝔼[Dj(Dj - 1)]/𝔼[Dj] 1. This confirms the heuristic argument of Newman, Strogatz, and Watts [Phys Rev E 64 (2002), 026118, 1–17]. In addition, the random fluctuations around this asymptotic mean log&ngr; N are characterized and shown to be uniformly bounded. In particular, we show convergence in distribution of the centered graph distance along exponentially growing subsequences. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2005