Jingyi Yan

Global Curvature Estimates for $\sigma_k$ Curvature Equations with $k\geq n/2$

We establish a new concavity inequality for the elementary symmetric function \(\sigma_k\), which controls the spectral quadratic form arising from the second variation of \(\log\lambda_{\max}\). The proof is based on an easy--hard decomposition of the spectral variables. The easy region is treated using an optimal con...