Thermofield-Bosonization on Compact Space
  We develop the construction of fermionic fields in terms of bosonic ones to describe free and interaction models in the circle, using thermofielddynamics. The description in the case of finite temperature is developed for both normal modes and zero modes. The treatment extends the thermofield-bosonization for periodic space. 
R. L. P. G. Amaral and L. V. Belvedere
hep-th