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SUMMARY:Simulation of Scalar Field Theories with Complex Actions
DTSTART;VALUE=DATE-TIME:20180724T211000Z
DTEND;VALUE=DATE-TIME:20180724T213000Z
DTSTAMP;VALUE=DATE-TIME:20210727T110332Z
UID:indico-contribution-34658@indico.fnal.gov
DESCRIPTION:Speakers: Michael Ogilvie (Washington University in St. Louis)
\nMany scalar field theory models with complex actions are invariant unde
r the antilinear ($\\mathcal{PT}$) symmetry operation $L^{*}(-\\chi)=L(\\c
hi)$. Models in this class include $i \\phi^3$\, the Bose gas at finite de
nsity and Polyakov loop spin models at finite density. This symmetry may b
e used to obtain a dual representation where weights in the functional int
egral are real but not necessarily positive. For a subclass of models sati
sfying a dual positive weight condition\, the sign problem is absent\; suc
h models are easily simulated by a simple local algorithm in any number of
dimensions. The existence of a positive representation is constrained by
Lee-Yang zeros\, and tied to the phase structure of a given model. Simula
tions of models in this subclass show a rich set of behaviors. Propagators
may exhibit damped oscillations\, indicating a clear violation of spectra
l positivity. Domain patterns may occur in equilibrium\, with both stripe
and bubble morphologies occurring. These behaviors appear to be likely in
finite density QCD in the vicinity of the critical line.\n\nhttps://indico
.fnal.gov/event/15949/contributions/34658/
LOCATION:Kellogg Hotel and Conference Center Centennial
URL:https://indico.fnal.gov/event/15949/contributions/34658/
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