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Grid/lib/qcd/utils/WilsonLoops.h
paboyle c399c2b44d Guido broke the charge conjugate plaquette action with premature optimisation.
This sector of the code does not matter for anything other than Guido's quenched HMC
studies, and any plaq specific optimisations should be retained in a private branch
instead of destroying the code simplicity.
2018-03-05 12:55:41 +00:00

658 lines
20 KiB
C++

/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./lib/qcd/utils/WilsonLoops.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>
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_UTILS_WILSON_LOOPS_H
#define QCD_UTILS_WILSON_LOOPS_H
namespace Grid {
namespace QCD {
// Common wilson loop observables
template <class Gimpl> class WilsonLoops : public Gimpl {
public:
INHERIT_GIMPL_TYPES(Gimpl);
typedef typename Gimpl::GaugeLinkField GaugeMat;
typedef typename Gimpl::GaugeField GaugeLorentz;
//////////////////////////////////////////////////
// directed plaquette oriented in mu,nu plane
//////////////////////////////////////////////////
static void dirPlaquette(GaugeMat &plaq, const std::vector<GaugeMat> &U,
const int mu, const int nu) {
// Annoyingly, must use either scope resolution to find dependent base
// class,
// or this-> ; there is no "this" in a static method. This forces explicit
// Gimpl scope
// resolution throughout the usage in this file, and rather defeats the
// purpose of deriving
// from Gimpl.
/*
plaq = Gimpl::CovShiftBackward(
U[mu], mu, Gimpl::CovShiftBackward(
U[nu], nu, Gimpl::CovShiftForward(U[mu], mu, U[nu])));
*/
// _
//|< _|
plaq = Gimpl::CovShiftForward(U[mu],mu,
Gimpl::CovShiftForward(U[nu],nu,
Gimpl::CovShiftBackward(U[mu],mu,
Gimpl::CovShiftIdentityBackward(U[nu], nu))));
}
//////////////////////////////////////////////////
// trace of directed plaquette oriented in mu,nu plane
//////////////////////////////////////////////////
static void traceDirPlaquette(ComplexField &plaq,
const std::vector<GaugeMat> &U, const int mu,
const int nu) {
GaugeMat sp(U[0]._grid);
dirPlaquette(sp, U, mu, nu);
plaq = trace(sp);
}
//////////////////////////////////////////////////
// sum over all planes of plaquette
//////////////////////////////////////////////////
static void sitePlaquette(ComplexField &Plaq,
const std::vector<GaugeMat> &U) {
ComplexField sitePlaq(U[0]._grid);
Plaq = zero;
for (int mu = 1; mu < Nd; mu++) {
for (int nu = 0; nu < mu; nu++) {
traceDirPlaquette(sitePlaq, U, mu, nu);
Plaq = Plaq + sitePlaq;
}
}
}
//////////////////////////////////////////////////
// sum over all x,y,z,t and over all planes of plaquette
//////////////////////////////////////////////////
static RealD sumPlaquette(const GaugeLorentz &Umu) {
std::vector<GaugeMat> U(Nd, Umu._grid);
// inefficient here
for (int mu = 0; mu < Nd; mu++) {
U[mu] = PeekIndex<LorentzIndex>(Umu, mu);
}
ComplexField Plaq(Umu._grid);
sitePlaquette(Plaq, U);
auto Tp = sum(Plaq);
auto p = TensorRemove(Tp);
return p.real();
}
//////////////////////////////////////////////////
// average over all x,y,z,t and over all planes of plaquette
//////////////////////////////////////////////////
static RealD avgPlaquette(const GaugeLorentz &Umu) {
RealD 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
}
//////////////////////////////////////////////////
// average over all x,y,z the temporal loop
//////////////////////////////////////////////////
static ComplexD avgPolyakovLoop(const GaugeField &Umu) { //assume Nd=4
GaugeMat Ut(Umu._grid), P(Umu._grid);
ComplexD out;
int T = Umu._grid->GlobalDimensions()[3];
int X = Umu._grid->GlobalDimensions()[0];
int Y = Umu._grid->GlobalDimensions()[1];
int Z = Umu._grid->GlobalDimensions()[2];
Ut = peekLorentz(Umu,3); //Select temporal direction
P = Ut;
for (int t=1;t<T;t++){
P = Gimpl::CovShiftForward(Ut,3,P);
}
RealD norm = 1.0/(Nc*X*Y*Z*T);
out = sum(trace(P))*norm;
return out;
}
//////////////////////////////////////////////////
// average over traced single links
//////////////////////////////////////////////////
static RealD linkTrace(const GaugeLorentz &Umu) {
std::vector<GaugeMat> U(Nd, Umu._grid);
ComplexField Tr(Umu._grid);
Tr = zero;
for (int mu = 0; mu < Nd; mu++) {
U[mu] = PeekIndex<LorentzIndex>(Umu, mu);
Tr = Tr + trace(U[mu]);
}
auto Tp = sum(Tr);
auto p = TensorRemove(Tp);
double vol = Umu._grid->gSites();
return p.real() / vol / 4.0 / 3.0;
};
//////////////////////////////////////////////////
// the sum over all staples on each site in direction mu,nu
//////////////////////////////////////////////////
static void Staple(GaugeMat &staple, const GaugeLorentz &Umu, int mu,
int nu) {
GridBase *grid = Umu._grid;
std::vector<GaugeMat> U(Nd, grid);
for (int d = 0; d < Nd; d++) {
U[d] = PeekIndex<LorentzIndex>(Umu, d);
}
staple = zero;
if (nu != mu) {
// mu
// ^
// |__> nu
// __
// |
// __|
//
staple += Gimpl::ShiftStaple(
Gimpl::CovShiftForward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[mu], mu, Gimpl::CovShiftIdentityBackward(U[nu], nu))),
mu);
// __
// |
// |__
//
//
staple += Gimpl::ShiftStaple(
Gimpl::CovShiftBackward(U[nu], nu,
Gimpl::CovShiftBackward(U[mu], mu, U[nu])),
mu);
}
}
// For the force term
/*
static void StapleMult(GaugeMat &staple, const GaugeLorentz &Umu, int mu) {
GridBase *grid = Umu._grid;
std::vector<GaugeMat> U(Nd, grid);
for (int d = 0; d < Nd; d++) {
// this operation is taking too much time
U[d] = PeekIndex<LorentzIndex>(Umu, d);
}
staple = zero;
GaugeMat tmp1(grid);
GaugeMat tmp2(grid);
for (int nu = 0; nu < Nd; nu++) {
if (nu != mu) {
// this is ~10% faster than the Staple -- PAB: so what it gives the WRONG answers for other BC's!
tmp1 = Cshift(U[nu], mu, 1);
tmp2 = Cshift(U[mu], nu, 1);
staple += tmp1* adj(U[nu]*tmp2);
tmp2 = adj(U[mu]*tmp1)*U[nu];
staple += Cshift(tmp2, nu, -1);
}
}
staple = U[mu]*staple;
}
*/
//////////////////////////////////////////////////
// the sum over all staples on each site
//////////////////////////////////////////////////
static void Staple(GaugeMat &staple, const GaugeLorentz &Umu, int mu) {
GridBase *grid = Umu._grid;
std::vector<GaugeMat> U(Nd, grid);
for (int d = 0; d < Nd; d++) {
U[d] = PeekIndex<LorentzIndex>(Umu, d);
}
staple = zero;
for (int nu = 0; nu < Nd; nu++) {
if (nu != mu) {
// mu
// ^
// |__> nu
// __
// |
// __|
//
staple += Gimpl::ShiftStaple(
Gimpl::CovShiftForward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[mu], mu, Gimpl::CovShiftIdentityBackward(U[nu], nu))),
mu);
// __
// |
// |__
//
//
staple += Gimpl::ShiftStaple(
Gimpl::CovShiftBackward(U[nu], nu,
Gimpl::CovShiftBackward(U[mu], mu, U[nu])), mu);
}
}
}
//////////////////////////////////////////////////
// the sum over all staples on each site in direction mu,nu, upper part
//////////////////////////////////////////////////
static void StapleUpper(GaugeMat &staple, const GaugeLorentz &Umu, int mu,
int nu) {
if (nu != mu) {
GridBase *grid = Umu._grid;
std::vector<GaugeMat> U(Nd, grid);
for (int d = 0; d < Nd; d++) {
U[d] = PeekIndex<LorentzIndex>(Umu, d);// some redundant copies
}
// mu
// ^
// |__> nu
// __
// |
// __|
//
staple = Gimpl::ShiftStaple(
Gimpl::CovShiftForward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[mu], mu, Gimpl::CovShiftIdentityBackward(U[nu], nu))),
mu);
}
}
////////////////////////////////////////////////////////////////////////
// the sum over all staples on each site in direction mu,nu, lower part
////////////////////////////////////////////////////////////////////////
static void StapleLower(GaugeMat &staple, const GaugeLorentz &Umu, int mu,
int nu) {
if (nu != mu) {
GridBase *grid = Umu._grid;
std::vector<GaugeMat> U(Nd, grid);
for (int d = 0; d < Nd; d++) {
U[d] = PeekIndex<LorentzIndex>(Umu, d);// some redundant copies
}
// mu
// ^
// |__> nu
// __
// |
// |__
//
//
staple = Gimpl::ShiftStaple(
Gimpl::CovShiftBackward(U[nu], nu,
Gimpl::CovShiftBackward(U[mu], mu, U[nu])),
mu);
}
}
//////////////////////////////////////////////////////
// Field Strength
//////////////////////////////////////////////////////
static void FieldStrength(GaugeMat &FS, const GaugeLorentz &Umu, int mu, int nu){
// Fmn +--<--+ Ut +--<--+
// | | | |
// (x)+-->--+ +-->--+(x) - h.c.
// | | | |
// +--<--+ +--<--+
GaugeMat Vup(Umu._grid), Vdn(Umu._grid);
StapleUpper(Vup, Umu, mu, nu);
StapleLower(Vdn, Umu, mu, nu);
GaugeMat v = Vup - Vdn;
GaugeMat u = PeekIndex<LorentzIndex>(Umu, mu); // some redundant copies
GaugeMat vu = v*u;
//FS = 0.25*Ta(u*v + Cshift(vu, mu, -1));
FS = (u*v + Cshift(vu, mu, -1));
FS = 0.125*(FS - adj(FS));
}
static Real TopologicalCharge(GaugeLorentz &U){
// 4d topological charge
assert(Nd==4);
// Bx = -iF(y,z), By = -iF(z,y), Bz = -iF(x,y)
GaugeMat Bx(U._grid), By(U._grid), Bz(U._grid);
FieldStrength(Bx, U, Ydir, Zdir);
FieldStrength(By, U, Zdir, Xdir);
FieldStrength(Bz, U, Xdir, Ydir);
// Ex = -iF(t,x), Ey = -iF(t,y), Ez = -iF(t,z)
GaugeMat Ex(U._grid), Ey(U._grid), Ez(U._grid);
FieldStrength(Ex, U, Tdir, Xdir);
FieldStrength(Ey, U, Tdir, Ydir);
FieldStrength(Ez, U, Tdir, Zdir);
double coeff = 8.0/(32.0*M_PI*M_PI);
ComplexField qfield = coeff*trace(Bx*Ex + By*Ey + Bz*Ez);
auto Tq = sum(qfield);
return TensorRemove(Tq).real();
}
//////////////////////////////////////////////////////
// Similar to above for rectangle is required
//////////////////////////////////////////////////////
static void dirRectangle(GaugeMat &rect, const std::vector<GaugeMat> &U,
const int mu, const int nu) {
rect = Gimpl::CovShiftForward(
U[mu], mu, Gimpl::CovShiftForward(U[mu], mu, U[nu])) * // ->->|
adj(Gimpl::CovShiftForward(
U[nu], nu, Gimpl::CovShiftForward(U[mu], mu, U[mu])));
rect = rect +
Gimpl::CovShiftForward(
U[mu], mu, Gimpl::CovShiftForward(U[nu], nu, U[nu])) * // ->||
adj(Gimpl::CovShiftForward(
U[nu], nu, Gimpl::CovShiftForward(U[nu], nu, U[mu])));
}
static void traceDirRectangle(ComplexField &rect,
const std::vector<GaugeMat> &U, const int mu,
const int nu) {
GaugeMat sp(U[0]._grid);
dirRectangle(sp, U, mu, nu);
rect = trace(sp);
}
static void siteRectangle(ComplexField &Rect,
const std::vector<GaugeMat> &U) {
ComplexField siteRect(U[0]._grid);
Rect = zero;
for (int mu = 1; mu < Nd; mu++) {
for (int nu = 0; nu < mu; nu++) {
traceDirRectangle(siteRect, U, mu, nu);
Rect = Rect + siteRect;
}
}
}
//////////////////////////////////////////////////
// sum over all x,y,z,t and over all planes of plaquette
//////////////////////////////////////////////////
static RealD sumRectangle(const GaugeLorentz &Umu) {
std::vector<GaugeMat> U(Nd, Umu._grid);
for (int mu = 0; mu < Nd; mu++) {
U[mu] = PeekIndex<LorentzIndex>(Umu, mu);
}
ComplexField Rect(Umu._grid);
siteRectangle(Rect, U);
auto Tp = sum(Rect);
auto p = TensorRemove(Tp);
return p.real();
}
//////////////////////////////////////////////////
// average over all x,y,z,t and over all planes of plaquette
//////////////////////////////////////////////////
static RealD avgRectangle(const GaugeLorentz &Umu) {
RealD sumrect = sumRectangle(Umu);
double vol = Umu._grid->gSites();
double faces = (1.0 * Nd * (Nd - 1)); // 2 distinct orientations summed
return sumrect / vol / faces / Nc; // Nd , Nc dependent... FIXME
}
//////////////////////////////////////////////////
// the sum over all staples on each site
//////////////////////////////////////////////////
static void RectStapleDouble(GaugeMat &U2, const GaugeMat &U, int mu) {
U2 = U * Cshift(U, mu, 1);
}
////////////////////////////////////////////////////////////////////////////
// Hop by two optimisation strategy does not work nicely with Gparity. (could
// do,
// but need to track two deep where cross boundary and apply a conjugation).
// Must differentiate this in Gimpl, and use Gimpl::isPeriodicGaugeField to do
// so .
////////////////////////////////////////////////////////////////////////////
static void RectStapleOptimised(GaugeMat &Stap, std::vector<GaugeMat> &U2,
std::vector<GaugeMat> &U, int mu) {
Stap = zero;
GridBase *grid = U[0]._grid;
GaugeMat Staple2x1(grid);
GaugeMat tmp(grid);
for (int nu = 0; nu < Nd; nu++) {
if (nu != mu) {
// Up staple ___ ___
// | |
tmp = Cshift(adj(U[nu]), nu, -1);
tmp = adj(U2[mu]) * tmp;
tmp = Cshift(tmp, mu, -2);
Staple2x1 = Gimpl::CovShiftForward(U[nu], nu, tmp);
// Down staple
// |___ ___|
//
tmp = adj(U2[mu]) * U[nu];
Staple2x1 += Gimpl::CovShiftBackward(U[nu], nu, Cshift(tmp, mu, -2));
// ___ ___
// | ___|
// |___ ___|
//
Stap += Cshift(Gimpl::CovShiftForward(U[mu], mu, Staple2x1), mu, 1);
// ___ ___
// |___ |
// |___ ___|
//
// tmp= Staple2x1* Cshift(U[mu],mu,-2);
// Stap+= Cshift(tmp,mu,1) ;
Stap += Cshift(Staple2x1, mu, 1) * Cshift(U[mu], mu, -1);
;
// --
// | |
//
// | |
tmp = Cshift(adj(U2[nu]), nu, -2);
tmp = Gimpl::CovShiftBackward(U[mu], mu, tmp);
tmp = U2[nu] * Cshift(tmp, nu, 2);
Stap += Cshift(tmp, mu, 1);
// | |
//
// | |
// --
tmp = Gimpl::CovShiftBackward(U[mu], mu, U2[nu]);
tmp = adj(U2[nu]) * tmp;
tmp = Cshift(tmp, nu, -2);
Stap += Cshift(tmp, mu, 1);
}
}
}
static void RectStaple(GaugeMat &Stap, const GaugeLorentz &Umu, int mu) {
RectStapleUnoptimised(Stap, Umu, mu);
}
static void RectStaple(const GaugeLorentz &Umu, GaugeMat &Stap,
std::vector<GaugeMat> &U2, std::vector<GaugeMat> &U,
int mu) {
if (Gimpl::isPeriodicGaugeField()) {
RectStapleOptimised(Stap, U2, U, mu);
} else {
RectStapleUnoptimised(Stap, Umu, mu);
}
}
static void RectStapleUnoptimised(GaugeMat &Stap, const GaugeLorentz &Umu,
int mu) {
GridBase *grid = Umu._grid;
std::vector<GaugeMat> U(Nd, grid);
for (int d = 0; d < Nd; d++) {
U[d] = PeekIndex<LorentzIndex>(Umu, d);
}
Stap = zero;
for (int nu = 0; nu < Nd; nu++) {
if (nu != mu) {
// __ ___
// | __ |
//
Stap += Gimpl::ShiftStaple(
Gimpl::CovShiftForward(
U[mu], mu,
Gimpl::CovShiftForward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[mu], mu,
Gimpl::CovShiftBackward(
U[mu], mu,
Gimpl::CovShiftIdentityBackward(U[nu], nu))))),
mu);
// __
// |__ __ |
Stap += Gimpl::ShiftStaple(
Gimpl::CovShiftForward(
U[mu], mu,
Gimpl::CovShiftBackward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[mu], mu, Gimpl::CovShiftBackward(U[mu], mu, U[nu])))),
mu);
// __
// |__ __ |
Stap += Gimpl::ShiftStaple(
Gimpl::CovShiftBackward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[mu], mu,
Gimpl::CovShiftBackward(
U[mu], mu, Gimpl::CovShiftForward(U[nu], nu, U[mu])))),
mu);
// __ ___
// |__ |
Stap += Gimpl::ShiftStaple(
Gimpl::CovShiftForward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[mu], mu,
Gimpl::CovShiftBackward(
U[mu], mu, Gimpl::CovShiftBackward(U[nu], nu, U[mu])))),
mu);
// --
// | |
//
// | |
Stap += Gimpl::ShiftStaple(
Gimpl::CovShiftForward(
U[nu], nu,
Gimpl::CovShiftForward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[mu], mu,
Gimpl::CovShiftBackward(
U[nu], nu,
Gimpl::CovShiftIdentityBackward(U[nu], nu))))),
mu);
// | |
//
// | |
// --
Stap += Gimpl::ShiftStaple(
Gimpl::CovShiftBackward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[nu], nu,
Gimpl::CovShiftBackward(
U[mu], mu, Gimpl::CovShiftForward(U[nu], nu, U[nu])))),
mu);
}
}
}
};
typedef WilsonLoops<PeriodicGimplR> ColourWilsonLoops;
typedef WilsonLoops<PeriodicGimplR> U1WilsonLoops;
typedef WilsonLoops<PeriodicGimplR> SU2WilsonLoops;
typedef WilsonLoops<PeriodicGimplR> SU3WilsonLoops;
}
}
#endif