Analytic Continuation of Spectral Functions for Small Systems
Abstract
The single particle spectral function for a finite many-particle system is, rigorously, a sum of delta-functions, but numerical analytic continuations of calculated temperature Green's functions for finite systems, using either MaxEnt or N-point Padé approximants, normally yield continuous spectral functions. Using a method of Bayesian spectral analysis due to Sivia and Carlile (J. Chem. Phys. 96), 170 (1992), we attempt to extract the underlying sharp lines from the temperature Green's functions for short Hubbard chains calculated in self-consistent fluctuation-exchange and parquet approximations, and hence to gain insight into finite-size effects in these approximations.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1996
- Bibcode:
- 1996APS..MAR.Q1914C