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arXiv · hep-lat/9709018

A fixed-point action for the lattice Schwinger model

C. B. Lang·T. K. Pany
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Abstract

We determine non-perturbatively a fixed-point (FP) action for fermions in the two-dimensional U(1) gauge (Schwinger) model. Our parameterization for the fermionic action has terms within a $7\times 7$ square on the lattice, using compact link variables. With the Wilson fermion action as starting point we determine the FP-action by iterating a block spin transformation (BST) with a blocking factor of 2 in the background of non-compact gauge field configurations sampled according to the (perfect) Gaussian measure. We simulate the model at various values of $β$ and find excellent improvement for the studied observables.

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C. B. Lang, T. K. Pany. 1997-09-09. A fixed-point action for the lattice Schwinger model. https://doi.org/10.1016/s0920-5632(97)00934-1

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