%0 Journal Article
%J Computer Physics Communications
%D 2013
%T Least square based method for obtaining one-particle spectral functions from temperature Green functions
%A Liu, J.
%K continuation
%K fermion systems
%K Global minimization
%K least square fit (NNLS)
%K model
%K Non-negative
%K One-particle spectral function
%K Pade analytic
%K quantum monte-carlo
%K Temperature Green function
%K Tikhonov regularization
%M WOS:000311661100011
%P 367-373
%R 10.1016/j.cpc.2012.09.019
%U ://WOS:000311661100011
%V 184
%X A least square based fitting scheme is proposed to extract an optimal one-particle spectral function from any one-particle temperature Green function. It uses the existing non-negative least square (NNLS) fit algorithm to do the fit, and Tikhonov regularization to help with possible numerical singular behaviors. By flexibly adding delta peaks to represent very sharp features of the target spectrum, this scheme guarantees a global minimization of the fitted residue. The performance of this scheme is manifested with diverse physical examples. The proposed scheme is shown to be comparable in performance to the standard Pade analytic continuation scheme. (C) 2012 Elsevier B.V. All rights reserved.
%Z ISI Document Delivery No.: 044YMTimes Cited: 0Cited Reference Count: 23Liu, JunUS Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering; US Department of Energy by Iowa State University [DE-AC02-07CH11358]The author would like to acknowledge Junyu Guo, Yi Xue, and Shina Tan for many useful discussions. He would also like to thank Prof. Kai-Ming Ho and Dr. Cai-Zhuang Wang for insightful discussions and kind help. Research supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering. Ames Laboratory is operated for the US Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358.Elsevier science bvAmsterdam
%8 02
%9 Article
%@ 0010-4655