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Grid/lib/qcd/utils/CovariantLaplacian.h

83 lines
2.4 KiB
C++

/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./lib/qcd/action/scalar/CovariantLaplacian.h
Copyright (C) 2016
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 COVARIANT_LAPLACIAN_H
#define COVARIANT_LAPLACIAN_H
namespace Grid {
namespace QCD {
template <class Impl>
class LaplacianAdjointField {
public:
INHERIT_GIMPL_TYPES(Impl);
typedef SU<Nc>::LatticeAlgebraVector AVector;
LaplacianAdjointField(GridBase* grid) : U(Nd, grid){};
void ImportGauge(const GaugeField& _U) {
for (int mu = 0; mu < Nd; mu++) {
U[mu] = PeekIndex<LorentzIndex>(_U, mu);
}
}
void Mdiag(const AVector& in, AVector& out) { assert(0); }
void Mdir(const AVector& in, AVector& out, int dir, int disp) { assert(0); }
void M(const AVector& in, AVector& out) {
double kappa = 0.99;
//Reconstruct matrix
GaugeLinkField tmp(in._grid);
GaugeLinkField tmp2(in._grid);
GaugeLinkField sum(in._grid);
GaugeLinkField out_mat(in._grid);
GaugeLinkField in_mat(in._grid);
SU<Nc>::FundamentalLieAlgebraMatrix(in, in_mat);
sum = zero;
for (int mu = 0; mu < Nd; mu++) {
tmp = U[mu] * Cshift(in_mat, mu, +1) * adj(U[mu]);
tmp2 = adj(U[mu]) * in_mat * U[mu];
sum += tmp + Cshift(tmp2, mu, -1) - 2.0 * in_mat;
}
out_mat = (1.0 - kappa) * in_mat - kappa/(double(4*Nd)) * sum;
// Project
SU<Nc>::projectOnAlgebra(out, out_mat);
}
private:
std::vector<GaugeLinkField> U;
};
}
}
#endif