Special Lagrangian submanifolds of log Calabi-Yau manifolds

Abstract

We study the existence of special Lagrangian submanifolds of log Calabi-Yau manifolds equipped with the complete Ricci-flat Kähler metric constructed by Tian-Yau. We prove that if $X$ is a Tian-Yau manifold, and if the compact Calabi-Yau manifold at infinty admits a single special Lagrangian, then $X$ admits infinitely many disjoint special Lagrangians. In complex dimension $2$, we prove that if $Y$ is a del Pezzo surface, or a rational elliptic surface, and $D\in |-K_Y|$ is a smooth divisor with $D^2=d$, then $X=Y\backslash D$ admits a special Lagrangian torus fibration, as conjectured by Strominger-Yau-Zaslow and Auroux. In fact, we show that $X$ admits twin special Lagrangian fibrations, confirming a prediction of Leung-Yau. In the special case that $Y$ is a rational elliptic surface, or $Y={\mathbb{P}}^2$ we identify the singular fibers for generic data, thereby confirming two conjectures of Auroux. Finally, we prove that after a hyper-Kähler rotation, $X$ can be compactified to the complement of a Kodaira type $I_d$ fiber appearing as a singular fiber in a rational elliptic surface $\check{\pi }:\check{Y}\to {\mathbb{P}}^1$.

70 pages. Updates and improvements. To appear in Duke Mathematical Journal