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arXiv · 2203.03733

Another look at the Balázs-Quastel-Seppäläinen theorem

Yu Gu·Tomasz Komorowski
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Abstract

We study the KPZ equation with a $1+1-$dimensional spacetime white noise, started at equilibrium, and give a different proof of the main result of \cite{bqs}, i.e., the variance of the solution at time $t$ is of order $t^{2/3}$. Instead of using a discrete approximation through the exclusion process and the second class particle, we utilize the connection to directed polymers in a random environment. Along the way, we show the annealed density of the stationary continuum directed polymer equals to the two-point covariance function of the stationary stochastic Burgers equation, confirming the physics prediction in \cite{MT}.

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Yu Gu, Tomasz Komorowski. 2022-10-26. Another look at the Balázs-Quastel-Seppäläinen theorem. https://arxiv.org/abs/2203.03733

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