Séminaire de Physique Théorique

An inextricable link : semi-classics and complex saddles

by Prof. Tin SULEJMANPASIC (North Carolina State University & IHÉS)

Amphithéâtre Léon Motchane (IHES)

Amphithéâtre Léon Motchane


35, route de Chartres, F-91440 Bures-sur-Yvette (France)

I will discuss the use of semi-classics and instanton calculus and argue that, contrary to common wisdom, complex solutions of the equations of motion are a necessary ingredient of semi-classical expansion. In particular, I will show that without the complex solutions semi-classical expansion of supersymmetric theories cannot be reconciled with the constraints of supersymmetry. This has a natural interpretation in the Picard-Lefschetz theory.