To study the deconfining phase transition at nonzero temperature, I outline
the perturbative construction of an effective theory for straight, thermal
Wilson lines. Certain large, time dependent gauge transformations play a
central role. They imply the existence of interfaces, which can be used to
determine the form of the effective theory as a gauged, nonlinear sigma model
of adjoint matrices. Especially near the transition, the Wilson line may
undergo a Higgs effect. As an adjoint field, this can generate eigenvalue
repulsion in the effective theory.Comment: 6 pages, LaTeX. Final, published version. Refs. 7, 39, and 40 added.
In Ref. 37, there is an expanded discussion of a "fuzzy" bag mode
