Complex projective threefolds with non-negative canonical Euler-Poincare characteristic

Abstract

Let $V$ be a complex nonsingular projective 3-fold of general type with $χ(ω_V)\geq 0$ (resp. $>0$). We prove that the m-canonical map $Φ_{|mK_V|}$ is birational onto its image for all $m\ge 14$ (resp. $\geq 8$). Known examples show that the lower bound $r_3=14$ (resp. $=8$) is optimal.