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Grid/lib/qcd/representations/two_index.h
Guido Cossu b6597b74e7 Added support for the Two index Symmetric and Antisymmetric representations
Tested for HMC convergence: OK
Added also a test file showing an example for mixed representations
2016-09-22 14:17:37 +01:00

100 lines
3.1 KiB
C++

/*
* Policy classes for the HMC
* Authors: Guido Cossu, David Preti
*/
#ifndef SUN2INDEX_H_H
#define SUN2INDEX_H_H
namespace Grid {
namespace QCD {
/*
* This is an helper class for the HMC
* Should contain only the data for the two index representations
* and the facility to convert from the fundamental -> two index
* The templated parameter TwoIndexSymmetry choses between the
* symmetric and antisymmetric representations
*
* There is an
* enum TwoIndexSymmetry { Symmetric = 1, AntiSymmetric = -1 };
* in the SUnTwoIndex.h file
*/
template <int ncolour, TwoIndexSymmetry S>
class TwoIndexRep {
public:
// typdef to be used by the Representations class in HMC to get the
// types for the higher representation fields
typedef typename SU_TwoIndex<ncolour, S>::LatticeTwoIndexMatrix LatticeMatrix;
typedef typename SU_TwoIndex<ncolour, S>::LatticeTwoIndexField LatticeField;
static const int Dimension = ncolour * (ncolour + S) / 2;
LatticeField U;
explicit TwoIndexRep(GridBase *grid) : U(grid) {}
void update_representation(const LatticeGaugeField &Uin) {
std::cout << GridLogDebug << "Updating TwoIndex representation\n";
// Uin is in the fundamental representation
// get the U in TwoIndexRep
// (U)_{(ij)(lk)} = tr [ adj(e^(ij)) U e^(lk) transpose(U) ]
conformable(U, Uin);
U = zero;
LatticeColourMatrix tmp(Uin._grid);
Vector<typename SU<ncolour>::Matrix> eij(Dimension);
for (int a = 0; a < Dimension; a++)
SU_TwoIndex<ncolour, S>::base(a, eij[a]);
for (int mu = 0; mu < Nd; mu++) {
auto Uin_mu = peekLorentz(Uin, mu);
auto U_mu = peekLorentz(U, mu);
for (int a = 0; a < Dimension; a++) {
tmp = transpose(Uin_mu) * adj(eij[a]) * Uin_mu;
for (int b = 0; b < Dimension; b++)
pokeColour(U_mu, trace(tmp * eij[b]), a, b);
}
pokeLorentz(U, U_mu, mu);
}
}
LatticeGaugeField RtoFundamentalProject(const LatticeField &in,
Real scale = 1.0) const {
LatticeGaugeField out(in._grid);
out = zero;
for (int mu = 0; mu < Nd; mu++) {
LatticeColourMatrix out_mu(in._grid); // fundamental representation
LatticeMatrix in_mu = peekLorentz(in, mu);
out_mu = zero;
typename SU<ncolour>::LatticeAlgebraVector h(in._grid);
projectOnAlgebra(h, in_mu, double(Nc + 2 * S)); // factor T(r)/T(fund)
FundamentalLieAlgebraMatrix(h, out_mu); // apply scale only once
pokeLorentz(out, out_mu, mu);
}
return out;
}
private:
void projectOnAlgebra(typename SU<ncolour>::LatticeAlgebraVector &h_out,
const LatticeMatrix &in, Real scale = 1.0) const {
SU_TwoIndex<ncolour, S>::projectOnAlgebra(h_out, in, scale);
}
void FundamentalLieAlgebraMatrix(
typename SU<ncolour>::LatticeAlgebraVector &h,
typename SU<ncolour>::LatticeMatrix &out, Real scale = 1.0) const {
SU<ncolour>::FundamentalLieAlgebraMatrix(h, out, scale);
}
};
typedef TwoIndexRep<Nc, Symmetric> TwoIndexSymmetricRepresentation;
typedef TwoIndexRep<Nc, AntiSymmetric> TwoIndexAntiSymmetricRepresentation;
}
}
#endif