
The tropical vertex group is generated by certain formal symplectomorphisms of the 2-dimensional algebraic torus. It plays a role in some problems in algebraic geometry and mathematical physics, e.g. wall-crossing. It is known that the group itself can be understood in many ways, for example in terms of "counting" certain rational curves or representations of quivers. This leads to nice correspondences. I will discuss joint work with M. Reineke and T. Weist in which we determine the "dual" of a remarkable formula of Manschot, Pioline and Sen for quiver representations: it is a degeneration formula in Gromov-Witten theory. If time permits I will also mention joint work in progress with S. A. Filippini in which we study the tropical counts underlying the group using an integral equation of Gaiotto, Moore and Neitzke.
Links:
[1] http://www.mpim-bonn.mpg.de/taxonomy/term/39
[2] http://www.mpim-bonn.mpg.de/node/3444
[3] http://www.mpim-bonn.mpg.de/node/2804