Speaker: Hadleigh Frost
Abstract: Quantum field theory does a good job of predicting the behaviour of small numbers of quantum particles. These calculations involve the combinatorics of graphs, which becomes intractable as the number of particles increases. We introduce a new approach to setting up these calculations using piecewise linear functions coming from tropical geometry. Surprisingly, we find this is well adapted for the limit of _large_ numbers of particles, where the calculations resemble the statistics of random walks. The results suggest that quantum field theory has a broader domain of application than we otherwise expect.