The Hamiltonian Approach to Yang‐Mills $(2+1):$ An Expansion Scheme, String Tension, etc. Available to Purchase

Yang‐Mills theories in $2+1$ (or 3) dimensions are interesting as nontrivial gauge theories in their own right and as effective theories of QCD at high temperatures. I shall review the basics of our Hamiltonian approach to this theory, emphasizing symmetries with a short update on its status. We will show that the calculation of the vacuum wave function for Yang‐Mills theory in $2+1$ dimensions is in the lowest order of a systematic expansion. Expectation values of observables can be calculated using an effective interacting chiral boson theory, which also leads to a natural expansion as a double series in the coupling constant (to be interpreted within a resummed perturbation series) and a particular kinematical factor. The calculation of the first set of corrections in this expansion shows that the string tension is modified by about $−0.3%$ to $−2.8%$ compared to the lowest order value. This is in good agreement with lattice estimates.