Sep 7 – 12, 2025
"Diament" Hotel
Europe/Warsaw timezone

Extracting spectral functions from imaginary time data - the analytic continuation problem revisited

Sep 8, 2025, 10:50 AM
40m
Chair: Peter Prelovsek

Chair: Peter Prelovsek

Invited talk

Speaker

Emanuel Gull (University of Warsaw & University of Michigan)

Description

Analytic continuation is a central step in the simulation of finite-temperature field theories in which numerically obtained imaginary-time data is continued to the real frequency axis for physical interpretation. Numerical analytic continuation is considered to be an ill-posed problem where uncertainties on the Matsubara axis are amplified exponentially. This talk introduces new class of algorithms, based on the mathematical framework of Nevanlinna theory combined with numerical methods from signal processing and control theory, which overcome the ill-posed nature of the problem and offer systematically improvable continuations, thereby facilitating the interpretation of computational results from finite-temperature field theories.

Primary author

Emanuel Gull (University of Warsaw & University of Michigan)

Presentation materials

There are no materials yet.