## Abstract

Sometimes a homology cycle of a nonsingular compactification manifold cannot be represented by a nonsingular submanifold. We want to know whether such nonrepresentable cycles can be wrapped by D-branes. A brane wrapping a representable cycle carries a K-theory charge if and only if its Freed-Witten anomaly vanishes. However some K-theory charges are only carried by branes that wrap nonrepresentable cycles. We provide two examples of Freed-Witten anomaly-free D6-branes wrapping nonrepresentable cycles in the presence of a trivial NS 3-form flux. The first occurs in type IIA string theory compactified on the Sp(2) group manifold and the second in IIA on a product of lens spaces. We find that the first D6-brane carries a K-theory charge while the second does not.

Original language | English (US) |
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Article number | 050 |

Journal | Journal of High Energy Physics |

Volume | 2006 |

Issue number | 10 |

DOIs | |

State | Published - Oct 1 2006 |

## Keywords

- D-branes
- Differential and Algebraic Geometry

## ASJC Scopus subject areas

- Nuclear and High Energy Physics