Brane-Antibrane Systems on Calabi-Yau Spaces

We propose a correspondence between brane-antibrane systems and stable triples (E_1,E_2,T), where E_1,E_2 are holomorphic vector bundles and the tachyon T is a map between them. We demonstrate that, under the assumption of holomorphicity, the brane-antibrane field equations reduce to a set of vortex equations, which are equivalent to the mathematical notion of stability of the triple. We discuss some examples and show that the theory of stable triples suggests a new notion of BPS bound states and stability, and curious relations between brane-antibrane configurations and wrapped branes in higher dimensions.