A Variational Principle in Discrete Space-Time - Existence of Minimizers
arXiv:math-ph/0503069 · doi:10.1007/s00526-006-0042-0
Abstract
We formulate a variational principle for a collection of projectors in an indefinite inner product space. The existence of minimizers is proved in various situations.
22 pages, LaTeX, clarifying footnote added on page 4