### 18.02.2015 (Wednesday)

#### Revisiting soliton contributions to perturbative amplitudes

Regular Seminar Costis Papageorgakis (Queen Mary University)

 at: 13:15 KCLroom G.01 abstract: It is often said that soliton contributions to perturbative processes in QFT are exponentially suppressed by a form-factor. We will provide a derivation of this form-factor by studying the soliton-antisoliton pair-production amplitude. This reduces to the calculation of a matrix element in the quantum mechanics on the soliton moduli space. We will investigate the conditions under which the latter leads to suppression. Extending this framework to instanton-solitons in five-dimensional Yang-Mills theory leaves open the possibility that such contributions will not be suppressed.