New instantons for matrix models
Marcos Mariño, Ricardo Schiappa, Maximilian Schwick
The complete, nonperturbative content of random matrix models is described by resurgent-transseries—general solutions to their corresponding string-equations. These transseries include exponentially-suppressed multi-instanton amplitudes obtained by eigenvalue tunneling, but they also contain exponentially-enhanced and mixed instanton-like sectors with no known matrix model interpretation. This work shows how these sectors can be also described by eigenvalue tunneling in matrix models—but on the non-physical sheet of the spectral curve describing their large-