Scheduling of Non-Colliding Random Walks

  • Riddhipratim BasuEmail author
  • Vladas Sidoravicius
  • Allan Sly
Conference paper
Part of the Springer Proceedings in Mathematics & Statistics book series (PROMS, volume 300)


On the complete graph \(\mathcal{{K}}_M\) with \(M \ge 3\) vertices consider two independent discrete time random walks \(\mathbb {X}\) and \(\mathbb {Y}\), choosing their steps uniformly at random. A pair of trajectories \(\mathbb {X} = \{ X_1, X_2, \dots \}\) and \(\mathbb {Y} = \{Y_1, Y_2, \dots \}\) is called non-colliding, if by delaying their jump times one can keep both walks at distinct vertices forever. It was conjectured by P. Winkler that for large enough M the set of pairs of non-colliding trajectories \(\{\mathbb {X},\mathbb {Y} \} \) has positive measure. N. Alon translated this problem to the language of coordinate percolation, a class of dependent percolation models, which in most situations is not tractable by methods of Bernoulli percolation. In this representation Winkler’s conjecture is equivalent to the existence of an infinite open cluster for large enough M. In this paper we establish the conjecture building upon the renormalization techniques developed in [4].


Dependent percolation Renormalization 



This work was completed when R.B. was a graduate student at the Department of Statistics at UC Berkeley and the result in this paper appeared in Chap. 3 of his Ph.D. dissertation at UC Berkeley: Lipschitz Embeddings of Random Objects and Related Topics, 2015. During the completion of this work R. B. was supported by UC Berkeley graduate fellowship, V. S. was supported by CNPq grant Bolsa de Produtividade, and A.S. was supported by NSF grant DMS–1352013. R.B. is currently supported by an ICTS-Simons Junior Faculty Fellowship and a Ramanujan Fellowship from Govt. of India and A.S. is supported by a Simons Investigator grant.


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Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  • Riddhipratim Basu
    • 1
    Email author
  • Vladas Sidoravicius
    • 2
    • 3
  • Allan Sly
    • 4
  1. 1.International Centre for Theoretical SciencesTata Institute of Fundamental ResearchBangaloreIndia
  2. 2.Courant Institute of Mathematical SciencesNew YorkUSA
  3. 3.NYU-ECNU Institute of Mathematical Sciences at NYU ShanghaiShanghaiChina
  4. 4.Department of MathematicsPrinceton UniversityPrincetonUSA

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