Volume 363 - 37th International Symposium on Lattice Field Theory (LATTICE2019) - Main session
The Hubbard model in the canonical formulation
U. Wenger,* S. Burri
*corresponding author
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Pre-published on: 2020 January 04
Published on:
Abstract
We describe non-relativistic fermions on the lattice (Hubbard model) in the canonical formulation using transfer matrices in fixed fermion number sectors such that the partition function becomes fully factorized in time. By analytically integrating out the auxiliary Hubbard-Stratanovich field due to the four-fermion interaction, we express the system in terms of discrete, local fermion occupation numbers which are the only remaining degrees of freedom. We show the close relation to the fermion loop and the fermion bag formulation. One can prove that in 1+1 dimension the fermion sign problem is absent. Finally, we construct improved estimators for the ground state energy, 2-point functions, and for the chemical potential.
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