Speaker
Katarina Trailović
(IJS)
Description
Picard–Lefschetz theory writes oscillatory integrals, such as real-time path integrals, as a sum over Lefschetz thimbles attached to complex saddle points. Each saddle is weighted by an intersection number, and computing these numbers in many dimensions has been a long-standing challenge. I will present a multiple shooting method that finds them reliably, including their signs. I will show it working on a three-variable Airy-type integral and on a discretized double-well path integral, where it identifies which nontrivial complex saddles contribute. In ongoing work, we use this approach to track how the contributions of bounces and bions change as time is continued from Euclidean to Lorentzian.
Author
Katarina Trailović
(IJS)