R440, Astronomy-Mathematics Building, NTU
(台灣大學天文數學館 440室)
On the Gaussian Asymptotics of the SHE and KPZ Equation in the Entire $L^{2}$-regime for Spatial Dimensions $d \geq 3$
Te-Chun Wang (University of Victoria)
Abstract
Phenomena of non-equilibrium growth processes are ubiquitous in nature. Many of these processes are believed to exhibit remarkably similar growth dynamics, which can be regarded as an interface that evolves with time, changing its roughness while being subjected to random noise. In the original 1986 paper of M. Kardar, G. Parisi and Y.-C. Zhang [2], the authors predicted the dynamic of these processes, and indicated that the evolution can be described by the solution
of a stochastic PDE, which is called the Kardar-Parisi-Zhang (KPZ) equation. On the other hand,
plays an important role in statistical mechanics. Roughly speaking, through the Cole–Hopf transform
,
can be regarded as the free energy of the continuous directed polymer model, which describes the behaviour of a hydrophilic polymer chain wafting in a disordered environment that contains randomly placed hydrophobic molecules as impurities. Here
plays the role of the partition function of this model, and solves a stochastic PDE, which is called
the stochastic heat equation (SHE).
In this talk, we will focus on the SHE and KPZ equation when spatial dimension
. In this case, both of the SHE and KPZ equation are quite sensitive to
, where
describes the strength of the white noise in these equations. Consequently, it is crucial to investigate the behavior of the SHE and KPZ equation for all
. In a recent paper of F. Comets, C. Cosco, and C. Mukherjee [1], the authors proved the limiting fluctuation of
under a restriction on
. Motivated by this result, in our recent work [3], we considered both
and
, and established their limiting fluctuations in the entire
-regime (i.e.,
). Here
is a critical value associated with the KPZ equation.
References
[1] F. Comets, C. Cosco, and C. Mukherjee. Space-time fluctuation of the Kardar-Parisi-Zhang equation in d ≥ 3 and the Gaussian free field. arXiv preprint, 2019. doi:10.48550/arXiv.1905.03200.
[3] T.-C. Wang. Space-time fluctuations for the SHE and KPZ equation in the entire L2-regime for spatial dimensions d ≥ 3. in preparation. 2023+.
WebEx Link: https://nationaltaiwanuniversity-ksz.my.webex.com/nationaltaiwanuniversity-ksz.my/j.php?MTID=md4cb1a957523794faa52a420d4a8cc6e
Meeting number (access code): 2512 470 0779
Meeting password: KHcPyYPC936