Dual lattice representations for O(N) and CP(N-1) models with a chemical potential

Understand

We derive dual representations for O(N) and CP(N-1) models on the lattice.

• In terms of the dual variables the partition sums have only real and positive contributions also at finite chemical potential.
• Thus the complex action problem of the conventional formulation is overcome and using the dual variables Monte Carlo simulations are possible at arbitrary chemical potential.