Tao probing the end of the world

Abstract

We introduce a new type IIB 5-brane description for the E-string theory which\nis the world-volume theory on the M5-brane probing the end of the world\nM9-brane. The E-string in the new realization is depicted as spiral 5-branes\nweb equipped with the cyclic structure which is key to uplifting to six\ndimensions. Utilizing the topological vertex to the 5-brane web configuration\nenables us to write down a combinatorial formula for the generating function of\nthe E-string elliptic genera, namely the full partition function of topological\nstrings on the local 1/2 K3 surface.\n