Thermal state on a cylindrical spacetime
  We proof that if we have a thermal equilibrium state on Minkowski spacetime in two dimensions then we have a thermal equilibrium state on the cylindrical spacetime obtained from this Minkowski spacetime by making 2\pi-periodic the spatial direction. We perform this by using the algebraic approach to Quantum Field Theory. 
L. Ort\'iz
math-ph hep-th math.MP quant-ph