Special Session 19: Topics on singular stochastic equations

Regularization by noise phenomena in stochastic nonlinear PDEs with modulated dispersion
Guopeng Li
Beijing Institute of Technology
Peoples Rep of China
Co-Author(s):    
Abstract:
In this talk, we first consider the Korteweg-de Vries equation (KdV) with a modulated dispersion. We observe the regularization-by-noise effects resulting from this modulation: we establish well-posedness of the modulated KdV on the circle in the regime where the unmodulated KdV is ill-posed. In particular, we show that the modulated KdV on the circle is locally well-posed in Sobolev spaces of arbitrarily low regularity, provided that the modulation is sufficiently irregular. Then I will present more recent results on the stochastic modulated KdV on the circle with multiplicative fractional-in-time noise, where we establish a new regularization-by-noise phenomenon on the stochastic convolution in a pathwise manner, where a gain of spatial regularity becomes (arbitrarily) larger for more irregular modulations. We then prove that the stochastic modulated KdV is pathwise locally well-posed in Sobolev spaces of arbitrarily low regularity, provided that the modulation is sufficiently irregular. If time permits, I will mention the results when the multiplicative noise is white-in-time. Based on joint works with Khalil Chouk (formerly Edinburgh), Massimiliano Gubinelli (Oxford), Jiawei Li & Tadahiro Oh (Edinburgh), and Andreia Chapouto (CNRS & Monash).