Lattice approach to the massive Thirring model with repulsive interaction

We consider the massive Thirring model with repulsive interaction on a lattice by taking a certain scaling limit of the six-vertex model on a square lattice. It is shown that, in contrast to the continuum model, the ground state can be constructed by the negative-energy pseudoparticles alone even for the repulsive case. The introduction of the negative-energy strings into the vacuum never causes instabilities. One-hole excitations and other kinds of excitations are calculated and compared with those of the continuum model. (orig.)