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Step size modification in HMC; ICC happy thread pragmas

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Peter Boyle
2018-12-20 09:32:33 +00:00
parent 35ed1defac
commit 2fcedb13dd
2 changed files with 38 additions and 7 deletions
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31
Grid/qcd/action/gauge/GaugeImplTypes.h
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@ -89,8 +89,39 @@ public:
// specific for SU gauge fields
LinkField Pmu(P.Grid());
Pmu = Zero();
//
// Zbigniew Srocinsky thesis:
// P(p) = N \Prod_{x\mu}e^-{1/2 Tr (p^2_mux)}
//
// p_x,mu = c_x,mu,a T_a
//
// Tr p^2 = sum_a,x,mu 1/2 (c_x,mu,a)^2
//
// Which implies P(p) = N \Prod_{x,\mu,a} e^-{1/4 c_xmua^2 }
//
// = N \Prod_{x,\mu,a} e^-{1/2 (c_xmua/sqrt{2})^2 }
//
// Expect cx' = cxmua/sqrt(2) to be a unit variance gaussian.
//
// Expect cxmua_new variance sqrt(2).
// Was variance cxmua_old variance 1
//
// tau_old * Pold = 1 = tau_old/sqrt(2) * [Pold * sqrt(2)]
// = tau_new * Pnew
//
// Hence tau_new = tau_cps = tau_guido/sqrt(2).
//
//
// Must scale the momentum by sqrt(2) up to invoke CPS and UKQCD conventions
//
//
// Hence expect cxmua = cx'*sqrt(2).
//
// Seek the scale parameter to be
for (int mu = 0; mu < Nd; mu++) {
SU<Nrepresentation>::GaussianFundamentalLieAlgebraMatrix(pRNG, Pmu);
RealD scale = ::sqrt(2) ;
Pmu = Pmu*scale;
PokeIndex<LorentzIndex>(P, Pmu, mu);
}
}