On Isospectral compactness in conformal class for 4-manifolds

Xianfu Liu, Zuoqin Wang

Let $(M,g_0)$ be a closed 4-manifold with positive Yamabe invariant and with $L^2$-small Weyl curvature tensor. Let $g_1\in [g_0]$ be any metric in the conformal class of $g_0$ w…