Tetrahedron instantons

Date: 2022-07-26

Time: 13:30 - 14:30


Xinyu Zhang


In this talk, I will discuss various aspects of tetrahedron instantons. Tetrahedron instantons are realized in type IIA superstring theory by bound states of D0-branes and four stacks of intersecting D6-branes with a suitable constant B-field. The tetrahedron instanton partition function admits an elegant closed-form expression depending only on the Omega-deformation parameters. Remarkably, the tetrahedron instanton partition function is equal to certain specialization of the magnificent four partition function, indicating the creation of intersecting D6-branes when a D8-brane annihilates with an anti-D8-brane. Meanwhile, the M-theory lift of our configuration is expected to be $mathbb{R} times X$, where $X$ is a noncompact Calabi-Yau fivefold and can be thought of as a superposition of Kaluza-Klein magnetic monopoles. We detect the property of $X$ using the index of M-theory on $X$, which coincides with the tetrahedron instanton partition function up to an appropriate perturbative factor. The talk is based on joint work with E. Pomoni and W. Yan.