Beijing Institute of Mathematical Sciences and Applications

In this talk, we consider the Cauchy problem for families of dispersive fluid models, including dispersive generalizations of the Benjamin-Ono equation and surface quasi-geostrophic (SQG) equation. A key property of both of these models is a null structure in the nonlinearity, which in particular implies the availability of a normal form transformation which can lessen impact of the nonlinearity. We discuss how paradifferential analysis allows the application of normal forms in the setting of these quasilinear fluid models. This talk discusses joint work with Grace Liu and Ovidiu-Neculai Avadanei.