The Vacuum in Light Cone Field Theory
نویسنده
چکیده
This is an overview of the problem of the vacuum in light-cone eld 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 eld 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 e ective Hamiltonians that incorporate vacuum physics, but that act in a Hilbert space in which the vacuum state is simple. The discussion is fairly informal, and focuses mainly on the conceptual issues. Additional technical details of the construction described here will appear in a forthcoming paper written with Kent Hornbostel. Talk presented at Orbis Scientiae 1996, Miami Beach, FL, January 25{28, 1996. To appear in the proceedings. Typeset using REVTEX
منابع مشابه
Vacuum Energies and Effective Potential in Light-Cone Field Theories
Vacuum energies are computed in light-cone field theories to obtain effective potentials which determine vacuum condensate. Quantization surfaces interpolating between the light-like surface and the usual spatial one are useful to define the vacuum energies unambiguously. The GrossNeveu, SU(N) Thirring, and O(N) vector models are worked out in the large N limit. The vacuum energies are found to...
متن کاملLight–Cone Quantization: Foundations and Applications
These lecture notes review the foundations and some applications of light– cone quantization. First I explain how to choose a time in special relativity. Inclusion of Poincaré invariance naturally leads to Dirac’s forms of relativistic dynamics. Among these, the front form, being the basis for light–cone quantization, is my main focus. I explain a few of its peculiar features such as boost and ...
متن کاملFermion Condensates and the Trivial Vacuum of Light-Cone Quantum Field Theory
We discuss the definition of condensates within light-cone quantum field theory. As the vacuum state in this formulation is trivial, we suggest to abstract vacuum properties from the particle spectrum. The latter can in principle be calculated by solving the eigenvalue problem of the light-cone Hamiltonian. We focus on fermionic condensates which are order parameters of chiral symmetry breaking...
متن کاملEffective light-front quantization of scalar field theories and two-dimensional electrodynamics.
We introduce a new method to include condensates in the light-cone Hamilto-nian. By using a Gaussian approximation to the ordinary vacuum in a theory close to the light front, we derive an effective Hamiltonian on the light cone, which has new terms reflecting the nontriviality of the vacuum. We demonstrate our method for scalar φ 4-theory and the massive Schwinger model.
متن کاملA model for SU (3) vacuum degeneracy using light-cone coordinates
Working in light-cone coordinates, we study the zero-modes and the vacuum in a 2 + 1 dimensional SU(3) gauge model. Considering the fields as independent of the tranverse variables, we dimensionally reduce this model to 1 + 1 dimensions. After introducing an appropriate su(3) basis and gauge conditions, we extract an adjoint field from the model. Quantization of this adjoint field and field equ...
متن کامل