Hamiltonian analysis of the unrestricted Higgs theory across kinetic-rank changes

Establish the nonlinear Hamiltonian constraint structure and physical degree-of-freedom count for the unrestricted adjoint-Higgs theory in regions where the field-dependent gauge kinetic operator has a rank different from its rank on the vacuum orbit, including a controlled low-energy matching to the exactly constrained theory after integrating out normal Higgs fields and their curvature couplings.

Background

The unrestricted adjoint-Higgs theory allows normal fluctuations away from the orbit of the vacuum configuration Φ=vJ\Phi=vJ. Away from that orbit, the field-dependent kinetic map is generally not an exact projector, and the canonical momenta of the coset connection no longer satisfy the primary constraints characteristic of the exactly constrained theory. Consequently, the regular Dirac analysis performed on the orbit-constrained field space cannot simply be extended by adding normal scalar canonical pairs.

The unresolved analysis is important because normal Higgs displacements can activate kinetic terms for connection components that are auxiliary on the vacuum orbit. A complete treatment must therefore analyze each region of constant kinetic rank, determine the associated constraints and degrees of freedom, and establish whether integrating out the normal Higgs fields yields a controlled effective description of the constrained model.

References

For the unrestricted Higgs theory, the main unresolved issue is the Hamiltonian analysis where the kinetic rank differs from its value on the vacuum orbit.

— Projected Yang-Mills Theory and the MacDowell-Mansouri Analogy  (2610.08566 - Alvarez, 6 Oct 2026) in Section 7, Summary and Discussion; see also Section 3.5, “Off-orbit kinetic rank and scope of the analysis”