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QedFVol: add functions for computing spatial and timelike Wilson loops

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This commit is contained in:
James Harrison 2016-11-14 17:51:53 +00:00
parent cf167d0cd1
commit f4ebea3381
2 changed files with 114 additions and 11 deletions
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117
programs/qed-fvol/WilsonLoops.h
View File

@ -45,7 +45,7 @@ public:
const std::vector<GaugeMat> &U) {
LatticeComplex sitePlaq(U[0]._grid);
Plaq = zero;
for (int mu = 1; mu < Nd; mu++) {
for (int mu = 1; mu < U[0]._grid->_ndimension; mu++) {
for (int nu = 0; nu < mu; nu++) {
traceDirPlaquette(sitePlaq, U, mu, nu);
Plaq = Plaq + sitePlaq;
@ -58,7 +58,7 @@ public:
static Real sumPlaquette(const GaugeLorentz &Umu) {
std::vector<GaugeMat> U(4, Umu._grid);
for (int mu = 0; mu < Nd; mu++) {
for (int mu = 0; mu < Umu._grid->_ndimension; mu++) {
U[mu] = PeekIndex<LorentzIndex>(Umu, mu);
}
@ -74,10 +74,11 @@ public:
// average over all x,y,z,t and over all planes of plaquette
//////////////////////////////////////////////////
static Real avgPlaquette(const GaugeLorentz &Umu) {
int ndim = Umu._grid->_ndimension;
Real sumplaq = sumPlaquette(Umu);
double vol = Umu._grid->gSites();
double faces = (1.0 * Nd * (Nd - 1)) / 2.0;
return sumplaq / vol / faces / Nc; // Nd , Nc dependent... FIXME
Real vol = Umu._grid->gSites();
Real faces = (1.0 * ndim * (ndim - 1)) / 2.0;
return sumplaq / vol / faces / Nc; // Nc dependent... FIXME
}
//////////////////////////////////////////////////
@ -123,7 +124,42 @@ public:
const int R1, const int R2) {
LatticeComplex siteWl(U[0]._grid);
Wl = zero;
for (int mu = 1; mu < Nd; mu++) {
for (int mu = 1; mu < U[0]._grid->_ndimension; mu++) {
for (int nu = 0; nu < mu; nu++) {
traceWilsonLoop(siteWl, U, R1, R2, mu, nu);
Wl = Wl + siteWl;
traceWilsonLoop(siteWl, U, R2, R1, mu, nu);
Wl = Wl + siteWl;
}
}
}
//////////////////////////////////////////////////
// sum over planes of Wilson loop with length R1
// in the time direction
//////////////////////////////////////////////////
static void siteTimelikeWilsonLoop(LatticeComplex &Wl,
const std::vector<GaugeMat> &U,
const int R1, const int R2) {
LatticeComplex siteWl(U[0]._grid);
int ndim = U[0]._grid->_ndimension;
Wl = zero;
for (int nu = 0; nu < ndim - 1; nu++) {
traceWilsonLoop(siteWl, U, R1, R2, ndim-1, nu);
Wl = Wl + siteWl;
}
}
//////////////////////////////////////////////////
// sum Wilson loop over all planes orthogonal to the time direction
//////////////////////////////////////////////////
static void siteSpatialWilsonLoop(LatticeComplex &Wl,
const std::vector<GaugeMat> &U,
const int R1, const int R2) {
LatticeComplex siteWl(U[0]._grid);
Wl = zero;
for (int mu = 1; mu < U[0]._grid->_ndimension - 1; mu++) {
for (int nu = 0; nu < mu; nu++) {
traceWilsonLoop(siteWl, U, R1, R2, mu, nu);
Wl = Wl + siteWl;
@ -139,7 +175,7 @@ public:
const int R1, const int R2) {
std::vector<GaugeMat> U(4, Umu._grid);
for (int mu = 0; mu < Nd; mu++) {
for (int mu = 0; mu < Umu._grid->_ndimension; mu++) {
U[mu] = PeekIndex<LorentzIndex>(Umu, mu);
}
@ -152,14 +188,75 @@ public:
return p.real();
}
//////////////////////////////////////////////////
// sum over all x,y,z,t and over all planes of timelike Wilson loop
//////////////////////////////////////////////////
static Real sumTimelikeWilsonLoop(const GaugeLorentz &Umu,
const int R1, const int R2) {
std::vector<GaugeMat> U(4, Umu._grid);
for (int mu = 0; mu < Umu._grid->_ndimension; mu++) {
U[mu] = PeekIndex<LorentzIndex>(Umu, mu);
}
LatticeComplex Wl(Umu._grid);
siteTimelikeWilsonLoop(Wl, U, R1, R2);
TComplex Tp = sum(Wl);
Complex p = TensorRemove(Tp);
return p.real();
}
//////////////////////////////////////////////////
// sum over all x,y,z,t and over all planes of spatial Wilson loop
//////////////////////////////////////////////////
static Real sumSpatialWilsonLoop(const GaugeLorentz &Umu,
const int R1, const int R2) {
std::vector<GaugeMat> U(4, Umu._grid);
for (int mu = 0; mu < Umu._grid->_ndimension; mu++) {
U[mu] = PeekIndex<LorentzIndex>(Umu, mu);
}
LatticeComplex Wl(Umu._grid);
siteSpatialWilsonLoop(Wl, U, R1, R2);
TComplex Tp = sum(Wl);
Complex p = TensorRemove(Tp);
return p.real();
}
//////////////////////////////////////////////////
// average over all x,y,z,t and over all planes of Wilson loop
//////////////////////////////////////////////////
static Real avgWilsonLoop(const GaugeLorentz &Umu,
const int R1, const int R2) {
int ndim = Umu._grid->_ndimension;
Real sumWl = sumWilsonLoop(Umu, R1, R2);
double vol = Umu._grid->gSites();
double faces = 1.0 * Nd * (Nd - 1);
return sumWl / vol / faces / Nc; // Nd , Nc dependent... FIXME
Real vol = Umu._grid->gSites();
Real faces = 1.0 * ndim * (ndim - 1);
return sumWl / vol / faces / Nc; // Nc dependent... FIXME
}
//////////////////////////////////////////////////
// average over all x,y,z,t and over all planes of timelike Wilson loop
//////////////////////////////////////////////////
static Real avgTimelikeWilsonLoop(const GaugeLorentz &Umu,
const int R1, const int R2) {
int ndim = Umu._grid->_ndimension;
Real sumWl = sumTimelikeWilsonLoop(Umu, R1, R2);
Real vol = Umu._grid->gSites();
Real faces = 1.0 * (ndim - 1);
return sumWl / vol / faces / Nc; // Nc dependent... FIXME
}
//////////////////////////////////////////////////
// average over all x,y,z,t and over all planes of spatial Wilson loop
//////////////////////////////////////////////////
static Real avgSpatialWilsonLoop(const GaugeLorentz &Umu,
const int R1, const int R2) {
int ndim = Umu._grid->_ndimension;
Real sumWl = sumSpatialWilsonLoop(Umu, R1, R2);
Real vol = Umu._grid->gSites();
Real faces = 1.0 * (ndim - 1) * (ndim - 2);
return sumWl / vol / faces / Nc; // Nc dependent... FIXME
}
};

8
programs/qed-fvol/qed-fvol.cc
View File

@ -64,7 +64,7 @@ int main(int argc, char *argv[])
EmField a(&grid);
EmField expA(&grid);
Real avgPlaqAexp, avgWl2x2Aexp;
Real avgPlaqAexp, avgWl2x2Aexp, avgWl2x2Aexp_time, avgWl2x2Aexp_space;
pRNG.SeedRandomDevice();
photon.StochasticField(a, pRNG);
@ -117,14 +117,20 @@ int main(int argc, char *argv[])
// Calculate plaquette from exponentiated photon field
avgPlaqAexp = NewWilsonLoops<QedPeriodicGimplR>::avgPlaquette(expA);
avgWl2x2Aexp = NewWilsonLoops<QedPeriodicGimplR>::avgWilsonLoop(expA, 2, 2);
avgWl2x2Aexp_time = NewWilsonLoops<QedPeriodicGimplR>::avgTimelikeWilsonLoop(expA, 2, 2);
avgWl2x2Aexp_space = NewWilsonLoops<QedPeriodicGimplR>::avgSpatialWilsonLoop(expA, 2, 2);
avgPlaqAexp = avgPlaqAexp*3;
avgWl2x2Aexp = avgWl2x2Aexp*3;
avgWl2x2Aexp_time = avgWl2x2Aexp_time*3;
avgWl2x2Aexp_space = avgWl2x2Aexp_space*3;
LOG(Message) << "Plaquette average (from A): " << avgPlaqA << std::endl;
LOG(Message) << "Plaquette average (from exp(A)): " << avgPlaqAexp << std::endl;
LOG(Message) << "2x2 Wilson Loop average (from A): " << avgWlA << std::endl;
LOG(Message) << "2x2 Wilson Loop average (from exp(A)): " << avgWl2x2Aexp << std::endl;
LOG(Message) << "2x2 Wilson Loop timelike average (from exp(A)): " << avgWl2x2Aexp_time << std::endl;
LOG(Message) << "2x2 Wilson Loop spatial average (from exp(A)): " << avgWl2x2Aexp_space << std::endl;
LOG(Message) << "Plaquette (one site): " << plaqsite / faces << std::endl;
// epilogue