evanberkowitz / supervillain

MCMC for modified Villain constructions
https://supervillain.readthedocs.io/
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Gauge transform v #83

Closed evanberkowitz closed 11 months ago

evanberkowitz commented 11 months ago

Since we have a gauge transformation $v \rightarrow v \pm W$ for each plaquette it is legal to transform any plaquette according to that rule. In fact, we could send $v \rightarrow v$ (mod $W$) without any physical effect. Furthermore when $W=1$ we should be able to absorb the entirety of $v$ into $m$.

While I was comparing the reference and production Spin_Spin implementation there was a disagreement, precisely because in the Worldline formulation we update $v$ even when $W=1$, and the production implementation was operating on Links while the reference was operating on bare $m$s. It ought to be possible to set $v \rightarrow 0$ at the expense of sending $m \rightarrow m - \delta v$ (in the $W=1$ case).