Solutions of the singular Yamabe problem near singular boundaries
Weiming Shen, Zhehui Wang, Jiongduo Xie
TL;DR
This work extends the asymptotic analysis of the singular Yamabe problem with negative scalar curvature to domains with singular boundaries and non-conformally flat backgrounds. By introducing a tangent cone framework and a near-identity diffeomorphism $T$, the authors establish a sharp first-order tangential approximation of local positive solutions by the cone model $u_V$, quantified as $|u(x)/u_V(Tx)-1|\le C d_g(x,0)$. They further develop higher-order expansions under enhanced regularity of $T$, reducing the problem to solving angular and outer-inner auxiliary problems and revealing a tripartite behavior dictated by the parameter $\mu_1$, with explicit leading correction terms involving $\xi_1$ and $\phi_1$. The paper also constructs no-tangential-decay examples to show the optimality of the results and delineates the limitations of tangential asymptotics in broader geometric settings. Overall, the results deepen our understanding of how boundary singularities and ambient curvature shape the near-boundary behavior of singular Yamabe solutions through tangent-cone approximations and degenerate elliptic-analytic techniques.
Abstract
In this paper, we investigate the asymptotic behaviors of solutions to the singular Yamabe problem with negative constant scalar curvature near singular boundaries and derive optimal estimates, where the background metrics are not assumed to be conformally flat. Specifically, we demonstrate that for a wide class of Lipschitz domains with asymptotic conical structure, the local positive solutions are well approximated by the positive solutions in the tangent cones at singular boundary points. This extends the results of [10, 12, 26].
