Faraday lines and observables for the Einstein-Maxwell theory
arXiv:gr-qc/9306024 · doi:10.1088/0264-9381/10/12/004
Abstract
In recent work on Einstein gravity in four dimensions using the Ashtekar variables, non-local loop variables have played an important role in attempts to formulate a quantum theory. The introduction of such variables is guided by gauge invariance, and here an infinite set of loop variables is introduced for the Hamiltonian form of the Einstein-Maxwell theory. The loops that enter the description naturally are the (source free) electric field lines. These variables are invariant under spatial diffeomorphisms and they also form a closed Poisson algebra. As such they may be useful for quantization attempts and for studying classical solutions.
8 pages, Alberta-Thy-30-93 (RevTeX)