On complex Langevin dynamics and zeroes of the measure I: Formal proof and simple models

Abstract

In the complex Langevin approach to lattice simulations at nonzero density, zeroes of the fermion determinant lead to a meromorphic drift and hence a need to revisit the theoretical derivation. We discuss how poles in the drift affect the formal justification of the approach and then explore the various potential issues in simple models, in a manner that is applicable to heavy dense and full QCD.

Comments: 7 pages, talk presented at the 34th International Symposium on Lattice Field Theory, 24-30 July 2016, University of Southampton, UK