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Full-Text Articles in Physics
Θ Vacua In The Light-Cone Schwinger Model, Alex C. Kalloniatis, David G. Robertson
Θ Vacua In The Light-Cone Schwinger Model, Alex C. Kalloniatis, David G. Robertson
Physics Faculty Scholarship
We discuss the bosonized Schwinger model in light-cone quantization, using discretization as an infrared regulator. We consider both the light-cone Coulomb gauge, in which all gauge freedom can be removed and a physical Hilbert space employed, and the light-cone Weyl (temporal) gauge, in which the Hilbert space is unphysical and a Gauss law operator is used to select a physical subspace. We describe the different ways in which the θ vacuum is manifested depending on this choice of gauge, and compute the θ-dependence of the chiral condensate in each case.
Light Front Qcd In (1+1)-Dimensions Coupled To Chiral Adjoint Fermions, David G. Robertson, Stephen S. Pinksy
Light Front Qcd In (1+1)-Dimensions Coupled To Chiral Adjoint Fermions, David G. Robertson, Stephen S. Pinksy
Physics Faculty Scholarship
We consider SU(N) gauge theory in 1+1 dimensions coupled to chiral fermions in the adjoint representation of the gauge group. With all fields in the adjoint representation the gauge group is actually , which possesses nontrivial topology. In particular, there are N distinct topological sectors and the physical vacuum state has a structure analogous to a θ vacuum. We show how this feature is realized in light-front quantization for the case N = 2, using discretization as an infrared regulator. In the discretized form of the theory the nontrivial vacuum structure is associated with the zero momentum mode of the …
The Vacuum In Light Cone Field Theory, David G. Robertson
The Vacuum In Light Cone Field Theory, David G. Robertson
Physics Faculty Scholarship
This is an overview of the problem of the vacuum in light-cone field theory, stressing its close connection to other puzzles regarding light-cone quantization. I explain the sense in which the light-cone vacuum is ``trivial,'' and describe a way of setting up a quantum field theory on null planes so that it is equivalent to the usual equal-time formulation. This construction is quite helpful in resolving the puzzling aspects of the light-cone formalism. It furthermore allows the extraction of effective Hamiltonians that incorporate vacuum physics, but that act in a Hilbert space in which the vacuum state is simple. The …