We study the classification of
smooth toroidal compactifications of nonuniform ball quotients in the sense of
Kodaira and Enriques. Several results concerning the Riemannian and complex
algebraic geometry of these spaces are given. In particular we show that there are
compact complex surfaces which admit Riemannian metrics of nonpositive curvature,
but which do not admit Kähler metrics of nonpositive curvature. An infinite
class of such examples arise as smooth toroidal compactifications of ball
quotients.
Keywords
manifolds with nonpositive curvature, toroidal
compactifications.