EXACT PARTITION-FUNCTION AND BOUNDARY STATE OF CRITICAL ISING-MODEL WITH BOUNDARY MAGNETIC-FIELD

We compute the exact partition function of the 2-D Ising Model at critical temperature but with nonzero magnetic field at the boundary. The model describes a renormalization group flow between the free and fixed conformal boundary conditions in the space of boundary interactions. For this flow the universal ground state degeneracy g and the full boundary state is computed exactly.