English

Universal record statistics for random walks and L\'evy flights with a nonzero staying probability

Statistical Mechanics 2021-09-08 v2 Mathematical Physics math.MP Probability

Abstract

We compute exactly the statistics of the number of records in a discrete-time random walk model on a line where the walker stays at a given position with a nonzero probability 0p10\leq p \leq 1, while with the complementary probability 1p1-p, it jumps to a new position with a jump length drawn from a continuous and symmetric distribution f0(η)f_0(\eta). We have shown that, for arbitrary pp, the statistics of records up to step NN is completely universal, i.e., independent of f0(η)f_0(\eta) for any NN. We also compute the connected two-time correlation function Cp(m1,m2)C_p(m_1, m_2) of the record-breaking events at times m1m_1 and m2m_2 and show it is also universal for all pp. Moreover, we demonstrate that Cp(m1,m2)<C0(m1,m2)C_p(m_1, m_2)< C_0(m_1, m_2) for all p>0p>0, indicating that a nonzero pp induces additional anti-correlations between record events. We further show that these anti-correlations lead to a drastic reduction in the fluctuations of the record numbers with increasing pp. This is manifest in the Fano factor, i.e. the ratio of the variance and the mean of the record number, which we compute explicitly. We also show that an interesting scaling limit emerges when p1p \to 1, NN \to \infty with the product t=(1p)Nt = (1-p)\, N fixed. We compute exactly the associated universal scaling functions for the mean, variance and the Fano factor of the number of records in this scaling limit. .

Keywords

Cite

@article{arxiv.2103.14062,
  title  = {Universal record statistics for random walks and L\'evy flights with a nonzero staying probability},
  author = {Satya N. Majumdar and Philippe Mounaix and Gregory Schehr},
  journal= {arXiv preprint arXiv:2103.14062},
  year   = {2021}
}

Comments

30 pages, 9 figures. Revised (and published) version. To appear in J. Phys. A

R2 v1 2026-06-24T00:33:59.428Z