Chern Flat and Chern Ricci-Flat Twisted Product Hermitian Manifolds

Let (M1,g) and (M2,h) be two Hermitian manifolds. The twisted product Hermitian manifold (M1xM2f,G) is the product manifold M1xM2 endowed with the Hermitian metric G=g+f2h, where f is a positive smooth function on M1xM2. In this paper, the Chern curvature, Chern Ricci curvature, Chern Ricci scalar curvature and holomorphic sectional curvature of the twisted product Hermitian manifold are derived. The necessary and sufficient conditions for the compact twisted product Hermitian manifold to have constant holomorphic sectional curvature are obtained. Under the condition that the logarithm of the twisted function is pluriharmonic, it is proved that the twisted product Hermitian manifold is Chern flat or Chern Ricci-flat, if and only if M1,g and M2,h are Chern flat or Chern Ricci-flat, respectively.