Complex langevin equation and the many-fermion problem

Chris Adami, Steven E. Koonin

Research output: Contribution to journalArticle

Abstract

We study the utility of a complex Langevin (CL) equation as an alternative for the Monte Carlo (MC) procedure in the evaluation of expectation values occurring in fermionic many-body problems. We find that a CL approach is natural in cases where nonpositive definite probability measures occur, and remains accurate even when the corresponding MC calculation develops a severe "sign problem." While the convergence of CL averages cannot be guaranteed in principle, we show how convergent results can be obtained in two simple quantum mechanical models, as well as a nontrivial schematic shell model path integral with multiple particles and a noncommuting interaction (the Lipkin model).

Original languageEnglish (US)
Pages (from-to)343191-3431910
Number of pages3088720
JournalPhysical Review C - Nuclear Physics
Volume63
Issue number3
DOIs
StatePublished - Mar 2001

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fermions
many body problem
circuit diagrams
evaluation
interactions

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Nuclear and High Energy Physics

Cite this

Complex langevin equation and the many-fermion problem. / Adami, Chris; Koonin, Steven E.

In: Physical Review C - Nuclear Physics, Vol. 63, No. 3, 03.2001, p. 343191-3431910.

Research output: Contribution to journalArticle

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