Induced Connections in Field Theory: The Odd Dimensional Yang-Mills Case
  We consider SU(N) Yang-Mills theories in 2n+1 Euclidean dimensions coupled to an even flavour-number of Dirac fermions. After integrating out the fermions the wave functional for the effective Yang-Mills theory inherits a non-trivial U(1)-connection which is computed in the limit of infinite fermion mass (adiabatic connection). Its Chern-class turns out to be just half the flavour number. Its topological origin is explained in the Lagrangean and Hamiltonian picture. 
Domenico Giulini