Navier-Stokes, Gross-Pitaevskii and Generalized Diffusion Equations using Stochastic Variational Method

Abstract: The stochastic variational method is applied to particle systems and continuum mediums. As the brief review of this method, we first discuss the application to particle Lagrangians and derive a diffusion-type equation and the Schr\"{o}dinger equation with the minimum gauge coupling. We further extend the application of the stochastic variational method to Lagrangians of continuum mediums and show that the Navier-Stokes, Gross-Pitaevskii and generalized diffusion equations are derived. The correction term for the Navier-Stokes equation is also obtained in this method. We discuss the meaning of this correction by comparing with the diffusion equation.