D-Branes on Calabi-Yau Manifolds
Paul S. Aspinwall
TL;DR
The work presents a comprehensive bridge between D-brane physics on Calabi–Yau threefolds and advanced algebraic geometry. It demonstrates that B-branes are captured by the derived category of coherent sheaves, with Pi-stability encoding physical stability and open-string spectra described by Ext groups. The text develops the Fukaya category for A-branes, explains the need for a triangulated, derived-category perspective to realize homological mirror symmetry, and applies the framework to Quintic, flops, and orbifolds, uncovering rich stability structures and monodromies. This synthesis provides a powerful, mathematically guided lens for understanding D-brane dynamics and mirror symmetry in string theory, with central tools including periods, Picard–Fuchs equations, and Fourier–Mukai transforms.
Abstract
In this review we study BPS D-branes on Calabi-Yau threefolds. Such D-branes naturally divide into two sets called A-branes and B-branes which are most easily understood from topological field theory. The main aim of this paper is to provide a self-contained guide to the derived category approach to B-branes and the idea of Pi-stability. We argue that this mathematical machinery is hard to avoid for a proper understanding of B-branes. A-branes and B-branes are related in a very complicated and interesting way which ties in with the ``homological mirror symmetry'' conjecture of Kontsevich. We motivate and exploit this form of mirror symmetry. The examples of the quintic 3-fold, flops and orbifolds are discussed at some length. In the latter case we describe the role of McKay quivers in the context of D-branes. These notes are to be submitted to the proceedings of TASI03.
