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arXiv · hep-th/9906242

Fractional Branes and Boundary States in Orbifold Theories

Duiliu-Emanuel Diaconescu·Jaume Gomis
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Abstract

We study the D-brane spectrum of N=2 string orbifold theories using the boundary state formalism. The construction is carried out for orbifolds with isolated singularities, non-isolated singularities and orbifolds with discrete torsion. Our results agree with the corresponding K-theoretic predictions when they are available and generalize them when they are not. This suggests that the classification of boundary states provides a sort of "quantum K-theory" just as chiral rings in CFT provide "quantum" generalizations of cohomology. We discuss the identification of these states with D-branes wrapping holomorphic cycles in the large radius limit of the CFT moduli space. The example C^3/Z_3 is worked out in full detail using local mirror symmetry techniques. We find a precise correspondence between fractional branes at the orbifold point and configurations of D-branes described by vector bundles on the exceptional P^2 cycle.

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Duiliu-Emanuel Diaconescu, Jaume Gomis. 1999-09-21. Fractional Branes and Boundary States in Orbifold Theories. https://doi.org/10.1088/1126-6708%2F2000%2F10%2F001

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