$BV$-Estimates for Non-Linear Parabolic PDE with Linear Drift
El Mahdi Erraji, Noureddine Igbida, Fahd Karami, Driss Meskine
TL;DR
The paper addresses space BV-regularity for a nonlinear parabolic PDE with a linear drift, modeled by $\frac{\partial u}{\partial t}-\Delta p+\nabla\cdot(uV)= f\in \beta(p)$ with $u\in\beta(p)$. An implicit Euler time discretization and analysis of a related stationary problem yield a weak solution $(u,p)$ and BV-control for the evolving density. Under stronger regularity assumptions on the drift and forcing, it proves local BV-estimates for $u$, and it shows a BV result for the stationary problem via a coercive, monotone framework; in the special case $\beta^{-1}\equiv 0$, the framework recovers BV for the linear transport equation. Together, these results provide compactness tools for stability and asymptotic analysis in drift-diffusion models on bounded domains, and offer a boundary-aware BV theory for nonlinear diffusion-drift PDEs.
Abstract
In the present work, we establish space Bounded Variation $(BV)$ regularity of the solution for a non-linear parabolic partial differential equations involving a linear drift term. We study the problem in a bounded domain with mixed Dirichlet-Neumann boundary conditions, a general non-linearity and reasonable assumptions on the data. Our results also cover, as a particular case, the linear transport equation in a bounded domain with an outward-pointing drift vector field on the boundary.
