English

Long and short time laws of iterated logarithms for the KPZ fixed point

Probability 2022-07-12 v1

Abstract

We consider the KPZ fixed point starting from a general class of initial data. In this article, we study the growth of the large peaks of the KPZ fixed point at a spatial point 00 when time tt goes to \infty and when tt approaches 11. We prove that for a very broad class of initial data, as tt\to \infty, the limsup of the KPZ fixed point height function when scaled by t1/3(loglogt)2/3t^{1/3}(\log\log t)^{2/3} almost surely equals a constant. The value of the constant is (3/4)2/3(3/4)^{2/3} or (3/2)2/3(3/2)^{2/3} depending on the initial data being non-random or Brownian respectively. Furthermore, we show that the increments of the KPZ fixed point near t=1t=1 admits a short time law of iterated logarithm. More precisely, as the time increments Δt:=t1\Delta t :=t-1 goes down to 00, for a large class of initial data including the Brownian data initial data, we show that limsup of the height increments the KPZ fixed point near time 11 when scaled by (Δt)1/3(loglog(Δt)1)2/3(\Delta t)^{1/3}(\log\log (\Delta t)^{-1})^{2/3} almost surely equals (3/2)2/3(3/2)^{2/3}.

Keywords

Cite

@article{arxiv.2207.04162,
  title  = {Long and short time laws of iterated logarithms for the KPZ fixed point},
  author = {Sayan Das and Promit Ghosal and Yier Lin},
  journal= {arXiv preprint arXiv:2207.04162},
  year   = {2022}
}

Comments

35 pages, no figures