Exact One-Loop Thermal Free Energies of Solitons

I show how to compute the exact one-loop thermal correction to the free energy of a soliton. The method uses the effective potential as an auxiliary step to ensure that the soliton is quantized around the appropriate vacuum. The exact result is then computed using scattering theory techniques, and includes all orders in the derivative expansion. It can be efficiently combined with a calculation of the exact quantum correction to yield the full free energy to one loop. I demonstrate this technique with explicit computations in $\phi^4$ models, obtaining the free energy for a kink in 1+1 dimensions and a domain wall in 2+1 dimensions.