J. Cao et F. Xavier, Kahler parabolicity and the Euler number of compact manifolds of non-positive sectional curvature, MATH ANNAL, 319(3), 2001, pp. 483-491
Let M-2n be a compact Riemannian manifold of non-positive sectional curvatu
re. It is shown that if M-2n is homeomorphic to a Kahler manifold, then its
Euler number satisfies the inequality (-1)(n)chi (M-2n) greater than or eq
ual to 0.