Gradient estimates for the $p$-Laplacian perfect conductivity problem with partially flat and $C^{1,{\hat{I}}^3}$ inclusions

Abstract

In this paper, we investigate the gradient estimates for solutions to the perfect conductivity problem with two closely spaced perfect conductors embedded in a homogeneous matrix, modeled by $p$-Laplacian elliptic equations. We first prove that the gradient of the solution remains bounded when the conductors possess partially ``flat" boundaries. This contrasts with the case involving strictly convex inclusions, where the gradient can blow up. Second, for conductors with $C^{1,{\hat{I}}^3}$ boundaries (${\hat{I}}^3\in (0,1)$), we establish both upper and lower bounds on the gradient, with optimal blow-up rates. Furthermore, we provide precise asymptotic expansions in some special cases.

23 pages