Special Session 146: Nonlinear differential equations: control, delay, and boundary value problems

An interpolation approach to $L^{\infty}$ a priori estimates for elliptic problems with nonlinearity on the boundary
Nsoki Mavinga
Swarthmore College
USA
Co-Author(s):    Maya Chhetri, Rosa Pardo
Abstract:
In this talk, we present an explicit $L^\infty(\Omega)$ a priori estimate for weak solutions to semilinear elliptic equations with nonlinearity on the boundary, in terms of the powers of their $H^1(\Omega)$ norms. We combine an appropriate version of a Moser iteration argument along with elliptic regularity and Gagliardo--Nirenberg interpolation inequality to prove our result. We illustrate our result with an application to subcritical problems satisfying Ambrosetti-Rabinowitz condition.