Renormalisation in the presence of variance blowup

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Hairer, Martin
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917875172769792
author Hairer, Martin
author_facet Hairer, Martin
contents We show that if one drives the KPZ equation by the derivative of a space-time white noise smoothened out at scale $\varepsilon \ll 1$ and multiplied by $\varepsilon^{3/4}$ then, as $\varepsilon \to 0$, solutions converge to the Cole-Hopf solutions to the KPZ equation driven by space-time white noise. In the same vein, we also show that if one drives an SDE by fractional Brownian motion with Hurst parameter $H < 1/4$, smoothened out at scale $\varepsilon \ll 1$ and multiplied by $\varepsilon^{1/4-H}$ then, as $\varepsilon \to 0$, solutions converge to an SDE driven by white noise. The mechanism giving rise to both results is the same, but the proof techniques differ substantially.
format Preprint
id arxiv_https___arxiv_org_abs_2401_10868
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Renormalisation in the presence of variance blowup
Hairer, Martin
Probability
60H10, 60H15, 60L20, 60L30
We show that if one drives the KPZ equation by the derivative of a space-time white noise smoothened out at scale $\varepsilon \ll 1$ and multiplied by $\varepsilon^{3/4}$ then, as $\varepsilon \to 0$, solutions converge to the Cole-Hopf solutions to the KPZ equation driven by space-time white noise. In the same vein, we also show that if one drives an SDE by fractional Brownian motion with Hurst parameter $H < 1/4$, smoothened out at scale $\varepsilon \ll 1$ and multiplied by $\varepsilon^{1/4-H}$ then, as $\varepsilon \to 0$, solutions converge to an SDE driven by white noise. The mechanism giving rise to both results is the same, but the proof techniques differ substantially.
title Renormalisation in the presence of variance blowup
topic Probability
60H10, 60H15, 60L20, 60L30
url https://arxiv.org/abs/2401.10868