2014/01/31 by Dominic Joyce · 2 citations
Mathematics · #math.DG #math.SG
paper · pdf · doi:10.4171/emss/8
published as EMS Surveys in Mathematical Sciences 2 (2015), 1-62 · 63 pages. (v2) new section 4 added, discussing exact Lagrangians, and the Kahler-Einstein case. To appear in EMS Surveys in Mathematical Sciences
arxiv created 2014/09/03 · arxiv updated 2015/06/05
Let M be a Calabi-Yau m-fold, and consider compact, graded Lagrangians L in M. Thomas and Yau math.DG/0104196, math.DG/0104197 conjectured that there should be a notion of "stability" for such L, and that if L is stable then Lagrangian mean curvature flow \Lt:t∈[0,∞)\ with L0=L should exist for all time, and L^∞=limt→∞Lt should be the unique special Lagrangian in the Hamiltonian isotopy class of L. This paper is an attempt to update the Thomas-Yau conjectures, and discuss related issues. It is a folklore conjecture that there exists a Bridgeland stability condition (Z,\mathcal P) on the derived Fukaya category Db\mathcal F(M) of M, such that an isomorphism class in Db\mathcal F(M) is (Z,\mathcal P)-semistable if (and possibly only if) it contains a special Lagrangian, which must then be unique. We conjecture that if (L,E,b) is an object in an enlarged version of Db\mathcal F(M), where L is a compact, graded Lagrangian in M (possibly immersed, or with "stable singularities"), E→ M a rank one local system, and b a bounding cochain for (L,E) in Lagrangian Floer cohomology, then there is a unique family \(Lt,Et,bt):t∈[0,∞)\ such that (L0,E0,b0)=(L,E,b), and (Lt,Et,bt)≅(L,E,b) in Db\mathcal F(M) for all t, and \Lt:t∈[0,∞)\ satisfies Lagrangian MCF with surgeries at singular times T1,T2,…, and in graded Lagrangian integral currents we have limt→∞Lt=L1+⋯+Ln, where Lj is a special Lagrangian integral current of phase eiπϕj for ϕ1>⋯>ϕn, and (L1,ϕ1),…,(Ln,ϕn) correspond to the decomposition of (L,E,b) into (Z,\mathcal P)-semistable objects. We also give detailed conjectures on the nature of the singularities of Lagrangian MCF that occur at the finite singular times T1,T2,….