# Mathematics Colloquia and Seminars

Return to Colloquia & Seminar listing

### Spectral networks, Strebel differentials, and non-Lagrangian QFT's

**QMAP Seminar**

Speaker: | Lotte Hollands, Heriot-Watt (Edinburgh) |

Related Webpage: | http://www.macs.hw.ac.uk/~lh33/index.html |

Location: | 2112 MSB |

Start time: | Fri, Oct 14 2016, 12:15PM |

BPS states in four-dimensional quantum field theories have a geometric interpretation in terms of so-called spectral networks on two-dimensional (punctured) Riemann surfaces. In this talk I will explain that the relevant spectral networks for non-Lagrangian theories can be generated from generalized Strebel differentials. I will describe how one can count the BPS states as special Lagrangian discs ending on the spectral network, and make this very concrete in one particularly interesting example, the E6 Minahan-Nemeschansky theory. Some rather beautiful pictures come up!

Bring lunch