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Krefl, Daniel (2009): Real Mirror Symmetry and The Real Topological String. Dissertation, LMU München: Fakultät für Physik



This thesis is concerned with real mirror symmetry, that is, mirror symmetry for a Calabi-Yau 3-fold background with a D-brane on a special Lagrangian 3-cycle defined by the real locus of an anti-holomorphic involution. More specifically, we will study real mirror symmetry by means of compact 1-parameter Calabi-Yau hypersurfaces in weighted projective space (at tree-level) and non-compact local P2 (at higher genus). For the compact models, we identify mirror pairs of D-brane configurations in weighted projective space, derive the corresponding inhomogeneous Picard-Fuchs equations, and solve for the domainwall tensions as analytic functions over moduli space, thereby collecting evidence for real mirror symmetry at tree-level. A major outcome of this part is the prediction of the number of disk instantons ending on the D-brane for these models. Further, we study real mirror symmetry at higher genus using local P2. For that, we utilize the real topological string, that is, the topological string on a background with O-plane and D-brane on top. In detail, we calculate topological amplitudes using three complementary techniques. In the A-model, we refine localization on the moduli space of maps with respect to the torus action preserved by the anti-holomorphic involution. This leads to a computation of open and unoriented Gromov-Witten invariants that can be applied to any toric Calabi-Yau with involution. We then show that the full topological string amplitudes can be reproduced within the topological vertex formalism. Especially, we obtain the real topological vertex with trivial fixed leg. Finally, we verify that the same results arise in the B-model from the extended holomorphic anomaly equations, together with appropriate boundary conditions, thereby establishing local real mirror symmetry at higher genus. Significant outcomes of this part are the derivation of real Gopakumar-Vafa invariants at high Euler number and degree for local P2 and the discovery of a new kind of gap structure of the closed and unoriented topological amplitudes at the conifold point in moduli space.