Supersymmetric Gauge Theories, Intersecting Branes and Free Fermions

Understand

We show that various holomorphic quantities in supersymmetric gauge theories can be conveniently computed by configurations of D4-branes and D6-branes.

• These D-branes intersect along a Riemann surface that is described by a holomorphic curve in a complex surface.
• The resulting I-brane carries two-dimensional chiral fermions on its world-volume.
• This system can be mapped directly to the topological string on a large class of non-compact Calabi-Yau manifolds.