Simultaneous desingularizations of Calabi-Yau and special Lagrangian 3-folds with conical singularities

Abstract

This paper is a follow-up to an earlier paper math.DG/0410260 on desingularizations of Calabi-Yau 3-folds with a conical singularity. In math.DG/0410260 we study Calabi-Yau 3-folds M_0 with a conical singularity at x modelled on some Calabi-Yau cone V, and construct a desingularization of M_0 by gluing in an Asymptotically Conical (AC) Calabi-Yau 3-fold Y to M_0 at x. In this paper, we shall investigate a similar desingularization problem on special Lagrangian (SL) 3-folds in the corresponding Calabi-Yau 3-folds. More precisely, suppose M_0 is now a Calabi-Yau 3-fold with finitely many conical singularities at x_i modelled on Calabi-Yau cones V_i for i=1,...,n, and N_0 an SL 3-fold in M_0 with conical singularities at the same points x_i modelled on SL cones C_i in V_i. Let Y_i be an AC Calabi-Yau 3-fold modelled on the Calabi-Yau cones V_i, and L_i an AC SL 3-fold in Y_i modelled on the SL cones C_i. We then simultaneously desingularize M_0 and N_0 by gluing in rescaled Y_i and L_i at each x_i. The construction is achieved by applying Joyce's analytic result [16, Thm. 5.3] on deforming Lagrangian submanifolds to nearby special Lagrangian submanifolds. As an application, we take M_0 to be the orbifold T^6/\mathbb{Z}_3 and construct some singular SL 3-folds N_0 in M_0 and AC SL 3-folds L_i in the corresponding Y_i, and glue them together to obtain examples of nonsingular SL 3-folds in the desingularized Calabi-Yau 3-folds.