1996/03/29 by David Robertson, Robertson, David G.
Physics and Astronomy · #Quantum Electrodynamics and Casimir Effect #Quantum and Classical Electrodynamics #Noncommutative and Quantum Gravity Theories
paper · pdf · doi:10.48550/arxiv.hep-th/9603205
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 discussion is fairly informal, and focuses mainly on the conceptual issues. [Talk presented at \sc Orbis Scientiae 1996, Miami Beach, FL, January 25--28, 1996. To appear in the proceedings.]