mirror of
https://github.com/paboyle/Grid.git
synced 2024-11-14 01:35:36 +00:00
97 lines
3.1 KiB
C++
97 lines
3.1 KiB
C++
/*************************************************************************************
|
|
|
|
Grid physics library, www.github.com/paboyle/Grid
|
|
|
|
Source file: ./lib/qcd/action/gauge/WilsonGaugeAction.h
|
|
|
|
Copyright (C) 2015
|
|
|
|
Author: Azusa Yamaguchi <ayamaguc@staffmail.ed.ac.uk>
|
|
Author: Peter Boyle <paboyle@ph.ed.ac.uk>
|
|
Author: neo <cossu@post.kek.jp>
|
|
Author: paboyle <paboyle@ph.ed.ac.uk>
|
|
Author: Guido Cossu <guido.cossu@ed.ac.uk>
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License along
|
|
with this program; if not, write to the Free Software Foundation, Inc.,
|
|
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
|
|
See the full license in the file "LICENSE" in the top level distribution
|
|
directory
|
|
*************************************************************************************/
|
|
/* END LEGAL */
|
|
#ifndef QCD_WILSON_GAUGE_ACTION_H
|
|
#define QCD_WILSON_GAUGE_ACTION_H
|
|
|
|
NAMESPACE_BEGIN(Grid);
|
|
|
|
////////////////////////////////////////////////////////////////////////
|
|
// Wilson Gauge Action .. should I template the Nc etc..
|
|
////////////////////////////////////////////////////////////////////////
|
|
template <class Gimpl>
|
|
class WilsonGaugeAction : public Action<typename Gimpl::GaugeField> {
|
|
public:
|
|
INHERIT_GIMPL_TYPES(Gimpl);
|
|
|
|
/////////////////////////// constructors
|
|
explicit WilsonGaugeAction(RealD beta_):beta(beta_){};
|
|
|
|
virtual std::string action_name() {return "WilsonGaugeAction";}
|
|
|
|
virtual std::string LogParameters(){
|
|
std::stringstream sstream;
|
|
sstream << GridLogMessage << "[WilsonGaugeAction] Beta: " << beta << std::endl;
|
|
return sstream.str();
|
|
}
|
|
|
|
virtual void refresh(const GaugeField &U,
|
|
GridParallelRNG &pRNG){}; // noop as no pseudoferms
|
|
|
|
virtual RealD S(const GaugeField &U) {
|
|
RealD plaq = WilsonLoops<Gimpl>::avgPlaquette(U);
|
|
RealD vol = U.Grid()->gSites();
|
|
RealD action = beta * (1.0 - plaq) * (Nd * (Nd - 1.0)) * vol * 0.5;
|
|
return action;
|
|
};
|
|
|
|
virtual void deriv(const GaugeField &U, GaugeField &dSdU) {
|
|
// not optimal implementation FIXME
|
|
// extend Ta to include Lorentz indexes
|
|
|
|
RealD factor = 0.5 * beta / RealD(Nc);
|
|
|
|
//GaugeLinkField Umu(U.Grid());
|
|
GaugeLinkField dSdU_mu(U.Grid());
|
|
for (int mu = 0; mu < Nd; mu++) {
|
|
|
|
GaugeLinkField Umu(U.Grid());
|
|
GaugeLinkField dSdU_mu(U.Grid());
|
|
for (int mu = 0; mu < Nd; mu++) {
|
|
Umu = PeekIndex<LorentzIndex>(U, mu);
|
|
|
|
// Staple in direction mu
|
|
WilsonLoops<Gimpl>::Staple(dSdU_mu, U, mu);
|
|
dSdU_mu = Ta(Umu * dSdU_mu) * factor;
|
|
|
|
PokeIndex<LorentzIndex>(dSdU, dSdU_mu, mu);
|
|
|
|
}
|
|
}
|
|
}
|
|
private:
|
|
RealD beta;
|
|
};
|
|
|
|
NAMESPACE_END(Grid);
|
|
#endif
|