The Refined Topological Vertex
arXiv:hep-th/0701156 · doi:10.1088/1126-6708/2009/10/069
Abstract
We define a refined topological vertex which depends in addition on a parameter, which physically corresponds to extending the self-dual graviphoton field strength to a more general configuration. Using this refined topological vertex we compute, using geometric engineering, a two-parameter (equivariant) instanton expansion of gauge theories which reproduce the results of Nekrasov. The refined vertex is also expected to be related to Khovanov knot invariants.
70 Pages, 23 Figures