TY - JOUR T1 - Solutions to the $\sigma_k$-Loewner-Nirenberg Problem on Annuli are Locally Lipschitz and Not Differentiable AU - Li , Yanyan AU - Nguyen , Luc JO - Journal of Mathematical Study VL - 2 SP - 123 EP - 141 PY - 2021 DA - 2021/02 SN - 54 DO - http://doi.org/10.4208/jms.v54n2.21.01 UR - https://global-sci.org/intro/article_detail/jms/18612.html KW - $\sigma_k$-Loewner-Nirenberg problem, $\sigma_k$-Yamabe problem, viscosity solution, regularity, conformal invariance. AB -

We show for $k \geq 2$ that the locally Lipschitz viscosity solution to the $\sigma_k$-Loewner-Nirenberg problem on a given annulus $\{a < |x| < b\}$ is $C^{1,\frac{1}{k}}_{\rm loc}$ in each of $\{a < |x| \leq \sqrt{ab}\}$ and $\{\sqrt{ab} \leq |x| < b\}$ and has a jump in radial derivative across $|x| = \sqrt{ab}$. Furthermore, the solution is not $C^{1,\gamma}_{\rm loc}$ for any $\gamma > \frac{1}{k}$. Optimal regularity for solutions to the $\sigma_k$-Yamabe problem on annuli with finite constant boundary values is also established.