preprint

Inserted: 11 jun 2025

Year: 2025

Abstract:

This paper investigates the asymptotic behavior of a class of nonlinear variational problems with Robin-type boundary conditions on a bounded Lipschitz domain. The energy functional contains a bulk term (the $p$-norm of the gradient), a boundary term (the $q$-norm of the trace) scaled by a parameter $\alpha>0$, and a linear source term. By variational methods, we derive first-order expansions of the minimum as $\alpha\to 0^+$ (Neumann limit) and as $\alpha\to+\infty$ (Dirichlet limit). In the Dirichlet limit, the energy converges to the one of Dirichlet problem with a power-type quantified rate (depending only on $q$), while the Neumann limit exhibits a dichotomy: under a compatibility condition, the energy linearly approaches the one of Neumann problem, otherwise, it diverges as a power of $\alpha$ depending only on $q$.