portelli/Grid
1
0
Fork 0
mirror of https://github.com/paboyle/Grid.git synced 2024-11-10 07:55:35 +00:00
Code Releases Activity

QedFVol: Implement infinite-volume photon

Browse Source
This commit is contained in:
James Harrison 2018-02-12 17:18:10 +00:00
parent 315f1146cd
commit 724cf02d4a
1 changed files with 97 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

113
lib/qcd/action/gauge/Photon.h
View File

@ -58,7 +58,7 @@ namespace QCD{
public:
INHERIT_GIMPL_TYPES(Gimpl);
GRID_SERIALIZABLE_ENUM(Gauge, undef, feynman, 1, coulomb, 2, landau, 3);
GRID_SERIALIZABLE_ENUM(ZmScheme, undef, qedL, 1, qedTL, 2);
GRID_SERIALIZABLE_ENUM(ZmScheme, undef, qedL, 1, qedTL, 2, qedInf, 3);
public:
Photon(Gauge gauge, ZmScheme zmScheme, std::vector<Real> improvements);
virtual ~Photon(void) = default;
@ -70,6 +70,7 @@ namespace QCD{
const GaugeLinkField &weight);
void UnitField(GaugeField &out);
private:
void infVolPropagator(GaugeLinkField &out);
void invKHatSquared(GaugeLinkField &out);
void zmSub(GaugeLinkField &out);
private:
@ -97,6 +98,33 @@ namespace QCD{
MomentumSpacePropagator(prop_k,in_k);
theFFT.FFT_all_dim(out,prop_k,FFT::backward);
}
template<class Gimpl>
void Photon<Gimpl>::infVolPropagator(GaugeLinkField &out)
{
auto *grid = dynamic_cast<GridCartesian *>(out._grid);
LatticeReal xmu(grid);
GaugeLinkField one(grid);
const unsigned int nd = grid->_ndimension;
std::vector<int> &l = grid->_fdimensions;
std::vector<int> x0(nd,0);
TComplex Tone = Complex(1.0,0.0);
TComplex Tzero = Complex(0.0,0.0);
FFT fft(grid);
one = Complex(1.0,0.0);
out = zero;
for(int mu = 0; mu < nd; mu++)
{
LatticeCoordinate(xmu,mu);
xmu = where(xmu < l[mu]/2.0, xmu, xmu-double(l[mu]));
out = out + toComplex(4*M_PI*M_PI*xmu*xmu);
}
pokeSite(Tone, out, x0);
out = one/out;
pokeSite(Tzero, out, x0);
fft.FFT_all_dim(out, out, FFT::forward);
}
template<class Gimpl>
void Photon<Gimpl>::invKHatSquared(GaugeLinkField &out)
@ -172,13 +200,28 @@ namespace QCD{
void Photon<Gimpl>::MomentumSpacePropagator(const GaugeField &in,
GaugeField &out)
{
GridBase *grid = out._grid;
LatticeComplex k2Inv(grid);
GridBase *grid = out._grid;
LatticeComplex momProp(grid);
invKHatSquared(k2Inv);
zmSub(k2Inv);
switch (zmScheme_)
{
case ZmScheme::qedTL:
case ZmScheme::qedL:
{
invKHatSquared(momProp);
zmSub(momProp);
break;
}
case ZmScheme::qedInf:
{
infVolPropagator(momProp);
break;
}
default:
break;
}
out = in*k2Inv;
out = in*momProp;
}
template<class Gimpl>
@ -188,14 +231,30 @@ namespace QCD{
const unsigned int nd = grid->_ndimension;
std::vector<int> latt_size = grid->_fdimensions;
Integer vol = 1;
for(int d = 0; d < nd; d++)
switch (zmScheme_)
{
vol = vol * latt_size[d];
case ZmScheme::qedTL:
case ZmScheme::qedL:
{
Integer vol = 1;
for(int d = 0; d < nd; d++)
{
vol = vol * latt_size[d];
}
invKHatSquared(weight);
weight = sqrt(vol*real(weight));
zmSub(weight);
break;
}
case ZmScheme::qedInf:
{
infVolPropagator(weight);
weight = sqrt(real(weight));
break;
}
default:
break;
}
invKHatSquared(weight);
weight = sqrt(vol*real(weight));
zmSub(weight);
}
template<class Gimpl>
@ -218,12 +277,34 @@ namespace QCD{
GaugeField aTilde(grid);
FFT fft(grid);
for(int mu = 0; mu < nd; mu++)
switch (zmScheme_)
{
gaussian(rng, r);
r = weight*r;
pokeLorentz(aTilde, r, mu);
case ZmScheme::qedTL:
case ZmScheme::qedL:
{
for(int mu = 0; mu < nd; mu++)
{
gaussian(rng, r);
r = weight*r;
pokeLorentz(aTilde, r, mu);
}
break;
}
case ZmScheme::qedInf:
{
Complex shift(1., 1.); // This needs to be a GaugeLink element?
for(int mu = 0; mu < nd; mu++)
{
bernoulli(rng, r);
r = weight*(2.*r - shift);
pokeLorentz(aTilde, r, mu);
}
break;
}
default:
break;
}
fft.FFT_all_dim(out, aTilde, FFT::backward);
out = real(out);