Probability Seminar

Younes ZineEPFL (École polytechnique fédérale de Lausanne)
Convergence problems for singular stochastic dynamics

Monday, November 6, 2023 - 4:15pm
Malott 406

Over the last twenty years there has been significant progress in the well-posedness study of singular stochastic PDEs in both parabolic and dispersive settings. In this talk, I will discuss some convergence problems for singular stochastic nonlinear PDEs. In a seminal work, Da Prato and Debussche (2003) established well-posedness of the stochastic quantization equation, also known as the parabolic Φ^k+1_2-model in the two-dimensional case. More recently, Gubinelli, Koch, Oh, and Tolomeo proved the corresponding well-posedness for the canonical stochastic quantization equation, also known as the hyperbolic Φ^k+1_2-model in the two-dimensional case. In the first part of this talk, I will describe convergence of the hyperbolic Φ^k+1_2-model to the parabolic Φ^k+1_2-model. In the dispersive setting, Bourgain (1996) established well-posedness for the dispersive Φ^4_2-model (=deterministic cubic nonlinear Schrödinger equation) on the two-dimensional torus with Gibbsian initial data. In the second part of the talk, I will discuss the convergence of the stochastic complex Ginzburg-Landau equation (= complex-valued version of the parabolic Φ^4_2-model) to the dispersive Φ^4_2-model at statistical equilibrium.