The quantum of action and finiteness of radiative corrections:   Deconfining SU(2) Yang-Mills thermodynamics
  The quantum of action $\hbar$, multiplying in certain powers perturbative vertices in 4D gauge theory, is related to the action of just-not-resolved selfdual and thermal gauge field configurations, calorons and anticalorons, of charge modulus unity. Appealing to the derivation of the effective theory for the deconfining phase of SU(2) Yang-Mills thermodynamics, we conclude that these vertex inducers convey a rapidly decreasing interaction strength between {\sl fundamental} plane waves when the momentum transfer is increased away from the scale of maximal, {\sl effective} resolution. This adds a deeper justification to the renormalization programme of perturbation theory which ignores the contribution to the partition function of nontrivially selfdual configurations. We also point out a connection between the QED fine-structure constant $\alpha$ and the electric-magnetically dual of the effective gauge coupling in the deconfining phase, and we illustrate the workings of effective loops in the expansion of the pressure. 
Ralf Hofmann and Dariush Kaviani
physics.gen-ph hep-th