Bethe-ansatz massive-Thirring-model thermodynamics: The weak-coupling limit

Using the Bethe-ansatz method we analyze the thermodynamic properties of the massive Thirring model in the zero-charge-sector attractive case, including the "charged vacuum" excitations introduced by Korepin. The energy of these excitations is calculated as a function of momentum and temperature and agrees with Korepin's results at $T=0\mathrm{}$. The specific heat is presented and shown to vary smoothly for the whole range of coupling in the attractive regime.