Deformations of maps with fixed target and curvature of direct image bundles

Abstract

Consider a smooth proper holomorphic fibration of complex manifolds. It is known that the semipositivity of the curvature of the direct image of the relative canonical bundle can be read in terms of the cup product with the Kodaira-Spencer class of the fibers. Motivated by this result, in this paper we study the relation between deformations of maps with fixed target and the curvature of certain direct image bundles. As a result, we find some curvature formulas and use them to prove a seminegativity result for a vector bundle of relative forms naturally related to the deformation data.