Subsonic Euler-Poisson flows with self-gravitation in an annulus

This paper concerns the steady Euler-Poisson system with self-gravitation in a two dimensional annulus of finite radius, which can be used to describe the expansion of disk-like stars and ring galaxies. Via the stream function, the Euler-Poisson system in the subsonic region is reformulated into a second order nonlinear elliptic system. One of the crucial ingredients of the analysis is to obtain the well-posedness of the boundary value problem for the associated linearized elliptic system, which is achieved through a special structure of the elliptic system to gain an energy estimate. By combining the iteration method with a priori estimates of solutions to the elliptic system, we establish the existence, uniqueness and nonlinear structural stability of subsonic flows. (c) 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.