Equivalence of Invariant metrics via Bergman kernel on complete noncompact K\"ahler manifolds

Abstract

We study equivalence of invariant metrics on noncompact K\"ahler manifolds with a complete Bergman metric of bounded curvature. Especially only the boundedness of the ratio between Bergman kernel and the $n$-times wedge product of Bergman metric in any fundamental domain of such a K\"ahler manifold is required to obtain the equivalence of the Bergman metric and the complete K\"ahler--Einstein metric. To demonstrate the effectiveness of this method, we consider a two-parameter family of $3$-dimensional bounded pseudoconvex domains \[ E_{p,\lambda}=\{(x,y,z)\in \mathbb{C}^3 ; (|x|^{2p}+|y|^2)^{1/{\lambda}}+|z|^2<1 \},\qquad p,\lambda>0.\] For this family, boundary limits of the holomorphic sectional curvature of the Bergman metric are not well-defined, and hence previously known methods for comparison of invariant metrics do not work. Lastly, we provide an estimate of lower bound of the integrated Carath\'eodory--Reiffen metric on complete noncompact simply-connected K\"ahler manifolds with negative sectional curvature.