PROBABILISTIC AND ANALYTICAL PROPERTIES OF THE LAST PASSAGE PERCOLATION CONSTANT IN A WEIGHTED RANDOM DIRECTED GRAPH



Foss, Sergey, Konstantopoulos, Takis and Pyatkin, Artem
(2023) PROBABILISTIC AND ANALYTICAL PROPERTIES OF THE LAST PASSAGE PERCOLATION CONSTANT IN A WEIGHTED RANDOM DIRECTED GRAPH. ANNALS OF APPLIED PROBABILITY, 33 (2). pp. 731-753.

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Abstract

To each edge (i, j), i < j, of the complete directed graph on the integers we assign unit weight with probability p or weight x with probability 1 − p, independently from edge to edge, and give to each path weight equal to the sum of its edge weights. If W0x,n is the maximum weight of all paths from 0 to n then W0x,n/n → Cp(x), as n → ∞, almost surely, where Cp(x) is positive and deterministic. We study Cp(x) as a function of x, for fixed 0 < p < 1, and show that it is a strictly increasing convex function that is not differentiable if and only if x is a nonpositive rational or a positive integer except 1 or the reciprocal of it. We allow x to be any real number, even negative, or, possibly, −∞. The case x = −∞ corresponds to the well-studied directed version of the Erdős–Rényi random graph (known as Barak–Erdős graph) for which Cp(−∞) = limx→−∞ Cp(x) has been studied as a function of p in a number of papers.

Item Type: Article
Uncontrolled Keywords: Random graph, maximal path, last-passage percolation, skeleton point, critical point, regenerative structure
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 02 Oct 2023 14:55
Last Modified: 17 Mar 2024 16:32
DOI: 10.1214/22-AAP1832
Open Access URL: https://arxiv.org/pdf/2006.01727.pdf
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3173311