English

Lower Deviations in $\beta$-ensembles and Law of Iterated Logarithm in Last Passage Percolation

Probability 2019-09-04 v1

Abstract

For the last passage percolation (LPP) on Z2\mathbb{Z}^2 with exponential passage times, let TnT_{n} denote the passage time from (1,1)(1,1) to (n,n)(n,n). We investigate the law of iterated logarithm of the sequence {Tn}n1\{T_{n}\}_{n\geq 1}; we show that lim infnTn4nn1/3(loglogn)1/3\liminf_{n\to \infty} \frac{T_{n}-4n}{n^{1/3}(\log \log n)^{1/3}} almost surely converges to a deterministic negative constant and obtain some estimates on the same. This settles a conjecture of Ledoux (J. Theor. Probab., 2018) where a related lower bound and similar results for the corresponding upper tail were proved. Our proof relies on a slight shift in perspective from point-to-point passage times to considering point-to-line passage times instead, and exploiting the correspondence of the latter to the largest eigenvalue of the Laguerre Orthogonal Ensemble (LOE). A key technical ingredient, which is of independent interest, is a new lower bound of lower tail deviation probability of the largest eigenvalue of β\beta-Laguerre ensembles, which extends the results proved in the context of the β\beta-Hermite ensembles by Ledoux and Rider (Electron. J. Probab., 2010).

Keywords

Cite

@article{arxiv.1909.01333,
  title  = {Lower Deviations in $\beta$-ensembles and Law of Iterated Logarithm in Last Passage Percolation},
  author = {Riddhipratim Basu and Shirshendu Ganguly and Milind Hegde and Manjunath Krishnapur},
  journal= {arXiv preprint arXiv:1909.01333},
  year   = {2019}
}

Comments

21 pages, 1 figure