The inviscid inflow-outflow problem via analyticity
Igor Kukavica, Wojciech Ożański, Marco Sammartino
TL;DR
We address the inviscid incompressible Euler equations with inflow-outflow boundary data on an analytic domain via an analytic framework that uses a time-dependent analyticity radius $\tau(t)$ and tangential derivatives. The main contribution is local well-posedness in analytic spaces without compatibility conditions across all dimensions, with a comprehensive extension to general analytic domains through product and pressure estimates and a derivative-reduction lemma. In 2D, global well-posedness is established under decay of the inflow field $\overline{u}$, leveraging persistence of analyticity to control nonlinear growth and vorticity. The results provide a robust, compatibility-free approach to inflow-outflow Euler problems and illuminate the role of analyticity in accommodating derivative loss and boundary interactions.
Abstract
We consider the incompressible Euler equation on an analytic domain $Ω$ with nonhomogeneous boundary condition $u\cdot \mathsf{n} = \overline{u} \cdot \mathsf{n}$ on $\partial Ω$, where $\overline{u}$ is a given divergence-free analytic vector field. We establish local well-posedness for $u$ in analytic spaces without any compatibility conditions in all space dimensions. We also prove global well-posedness in the 2D case if $\overline{u}$ decays in time sufficiently fast.
