When: Thursday, November 5, 2020, 3:00 PM - 4:00 PMWhere: Zoom
In string theory SL(2,Z) invariant functions, such as modular graph functions or coefficient functions of higher derivative corrections, are ubiquitous. Using a representation in terms of Poincaré series we can combine different methods for asymptotic expansions and obtain the complete perturbative and non-perturbative expansion. In the case of the higher derivative corrections, these terms have an interpretation in terms of perturbative string loop effects and pairs of instantons/anti-instantons.