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Grid/lib/qcd/smearing/APEsmearing.h
2016-10-14 17:22:32 +01:00

131 lines
4.0 KiB
C++

/*!
@brief Declaration of Smear_APE class for APE smearing
*/
#ifndef APE_SMEAR_
#define APE_SMEAR_
namespace Grid {
namespace QCD {
/*! @brief APE type smearing of link variables. */
template <class Gimpl>
class Smear_APE: public Smear<Gimpl>{
private:
const std::vector<double> rho;/*!< Array of weights */
//This member must be private - we do not want to control from outside
std::vector<double> set_rho(const double common_rho) const {
std::vector<double> res;
for(int mn=0; mn<Nd*Nd; ++mn) res.push_back(common_rho);
for(int mu=0; mu<Nd; ++mu) res[mu + mu*Nd] = 0.0;
return res;
}
public:
// Defines the gauge field types
INHERIT_GIMPL_TYPES(Gimpl)
// Constructors and destructors
Smear_APE(const std::vector<double>& rho_):rho(rho_){} // check vector size
Smear_APE(double rho_val):rho(set_rho(rho_val)){}
Smear_APE():rho(set_rho(1.0)){}
~Smear_APE(){}
///////////////////////////////////////////////////////////////////////////////
void smear(GaugeField& u_smr, const GaugeField& U)const{
GridBase *grid = U._grid;
GaugeLinkField Cup(grid), tmp_stpl(grid);
WilsonLoops<Gimpl> WL;
u_smr = zero;
for(int mu=0; mu<Nd; ++mu){
Cup = zero;
for(int nu=0; nu<Nd; ++nu){
if (nu != mu) {
// get the staple in direction mu, nu
WL.Staple(tmp_stpl, U, mu, nu); //nb staple conventions of IroIro and Grid differ by a dagger
Cup += tmp_stpl*rho[mu + Nd * nu];
}
}
// save the Cup link-field on the u_smr gauge-field
pokeLorentz(u_smr, adj(Cup), mu); // u_smr[mu] = Cup^dag see conventions for Staple
}
}
////////////////////////////////////////////////////////////////////////////////
void derivative(GaugeField& SigmaTerm,
const GaugeField& iLambda,
const GaugeField& U)const{
// Reference
// Morningstar, Peardon, Phys.Rev.D69,054501(2004)
// Equation 75
// Computing Sigma_mu, derivative of S[fat links] with respect to the thin links
// Output SigmaTerm
GridBase *grid = U._grid;
WilsonLoops<Gimpl> WL;
GaugeLinkField staple(grid), u_tmp(grid);
GaugeLinkField iLambda_mu(grid), iLambda_nu(grid);
GaugeLinkField U_mu(grid), U_nu(grid);
GaugeLinkField sh_field(grid), temp_Sigma(grid);
Real rho_munu, rho_numu;
for(int mu = 0; mu < Nd; ++mu){
U_mu = peekLorentz( U, mu);
iLambda_mu = peekLorentz(iLambda, mu);
for(int nu = 0; nu < Nd; ++nu){
if(nu==mu) continue;
U_nu = peekLorentz( U, nu);
iLambda_nu = peekLorentz(iLambda, nu);
rho_munu = rho[mu + Nd * nu];
rho_numu = rho[nu + Nd * mu];
WL.StapleUpper(staple, U, mu, nu);
temp_Sigma = -rho_numu*staple*iLambda_nu; //ok
//-r_numu*U_nu(x+mu)*Udag_mu(x+nu)*Udag_nu(x)*Lambda_nu(x)
Gimpl::AddLink(SigmaTerm, temp_Sigma, mu);
sh_field = Cshift(iLambda_nu, mu, 1);// general also for Gparity?
temp_Sigma = rho_numu*sh_field*staple; //ok
//r_numu*Lambda_nu(mu)*U_nu(x+mu)*Udag_mu(x+nu)*Udag_nu(x)
Gimpl::AddLink(SigmaTerm, temp_Sigma, mu);
sh_field = Cshift(iLambda_mu, nu, 1);
temp_Sigma = -rho_munu*staple*U_nu*sh_field*adj(U_nu); //ok
//-r_munu*U_nu(x+mu)*Udag_mu(x+nu)*Lambda_mu(x+nu)*Udag_nu(x)
Gimpl::AddLink(SigmaTerm, temp_Sigma, mu);
staple = zero;
sh_field = Cshift(U_nu, mu, 1);
temp_Sigma = -rho_munu*adj(sh_field)*adj(U_mu)*iLambda_mu*U_nu;
temp_Sigma += rho_numu*adj(sh_field)*adj(U_mu)*iLambda_nu*U_nu;
u_tmp = adj(U_nu)*iLambda_nu;
sh_field = Cshift(u_tmp, mu, 1);
temp_Sigma += -rho_numu*sh_field*adj(U_mu)*U_nu;
sh_field = Cshift(temp_Sigma, nu, -1);
Gimpl::AddLink(SigmaTerm, sh_field, mu);
}
}
}
};
}// namespace QCD
}//namespace Grid
#endif