Special Lagrangian submanifolds with isolated conical singularities. V. Survey and applications

Abstract

This is the last in a series of five papers math.DG/0211294, math.DG/0211295, math.DG/0302355, math.DG/0302356 studying compact special Lagrangian submanifolds (SL m-folds) X in (almost) Calabi-Yau m-folds M with singularities x_1,...,x_n locally modelled on special Lagrangian cones C_1,...,C_n in C^m with isolated singularities at 0. Readers are advised to begin with this paper. We survey the major results of the previous four papers, giving brief explanations of the proofs. We apply the results to describe the boundary of a moduli space of compact, nonsingular SL m-folds N in M. We prove the existence of special Lagrangian connected sums N_1 # ... # N_k of SL m-folds N_1,...,N_k in M. We also study SL 3-folds with T^2-cone singularities, proving results related to ideas of the author on invariants of Calabi-Yau 3-folds and the SYZ Conjecture. Let X be a compact SL m-fold with isolated conical singularities x_i and cones C_i for i=1,...,n. The first paper math.DG/0211294 studied the regularity of X near its singular points, and the the second paper math.DG/0211295 the moduli space of deformations of X. The third and fourth papers math.DG/0302355, math.DG/0302356 construct desingularizations of X, realizing X as a limit of a family of compact, nonsingular SL m-folds N^t in M for small t>0. Let L_i be an Asymptotically Conical SL m-fold in C^m asymptotic to C_i at infinity. We make N^t by gluing tL_i into X at x_i for i=1,...n.