Skip to content
Preprint

Independence Threshold for Collision Times of Many Planar Random Walks

Sep 2026 · 1 citation · 12 references
Mathematics Physics

Abstract

We study collision times of many independent simple random walks on $\mathbb Z^2$ through the joint moment generating function of their pairwise collision local times. For a fixed number of walks, these collision times are known to be asymptotically independent after a suitable logarithmic normalisation. We investigate the extent to which this independence persists when the number of walks grows. For $N$ being the walk length, our results identify a threshold $\asymp (\log N)^{\frac{1}{3}}$, on which the transition from independence to dependence happens. The proofs combine chaos expansion techniques and a correlation inequality, which is the result of a local limit theorem.

View source

Similar papers

Preprint Oct 2026

Scaling limit of the collision measure for two-dimensional random walks

We study the scaling limit of the collision measure of two i.i.d. discrete-time random walks on $\mathbb Z^2$, which records their collision sites and times. This is a critical regime for collisions: the walks collide infinitely often, whereas the limiting Brownian motions do not collide at positive times. Hence, exist...

S. Nakajima, Ryoichiro Noda · 0 citations
Preprint Aug 2026

Interface between competing random walks on a cycle

We consider a competition between two independent random walks on a cycle of length $N$. Each vertex is claimed by the walker that visits it first, and remains claimed thereafter. We prove that if the initial distance between the walkers is $d$, then the expected number of edges whose endpoints are claimed by different...

S. Chatterjee, Nadya Nabahi, Grigory Terlov · 1 citation
Preprint Oct 2026

Shape theorem for excited random walks on the integer lattice

We study the limit shape of the range of the random walk excited to the center on $\mathbb Z^d$, with $d\geq2$. A cookie is placed at each nonzero vertex. On its first visit to such a vertex, the walker consumes the cookie and takes its next nearest-neighbor step with a bias toward the origin. On a visit to the origin,...

Tuan-Minh Nguyen · 2 citations
Preprint Sep 2026

Intersection Exponents of Simple Random Walks in Two and Three Dimensions

The probability that several independent random walks avoid one another decays algebraically with the number of steps $N\to\infty$ in two and three dimensions, $P_N\sim N^{-\xi/2}$, where the intersection exponent $\xi$ depends on the number of random walks. More generally, one may consider several groups of independen...

Qi-Yuan Shi, Run-Sheng Liu, Xin-Yi Li et al. · 0 citations
Preprint Oct 2026

A limit law for the cover time of the two-dimensional discrete torus

We determine the limiting distribution of the cover time of simple random walk on the two-dimensional discrete torus. For the continuous-time walk with total jump rate one on $(\mathbb Z/N\mathbb Z)^2$, let $T_N$ denote its cover time. We prove that $\frac{T_N}{(2/\pi)N^2\log N}-2\log N+\log\log N \Longrightarrow G+\lo...

Ye Zhou · 0 citations
Preprint Aug 2026

Recurrence and capacity of stable branching random walks

We study the linear growth rate of the range of size-conditioned Branching Random Walks (BRW) when the offspring distribution $\mu$ is critical and attracted to an $\alpha$-stable law. This is done via the infinite invariant BRW introduced by Le Gall&Lin and a new criterion which relates this growth rate of the range t...

Antoine Aurillard · 0 citations

We use cookies to run the site and, with your consent, for analytics and to show ads. See our Cookie Policy.