1999/04/30 by Fotini Markopoulou · 2 citations
Physics and Astronomy · #hep-th #gr-qc
paper · pdf · doi:10.1088/0264-9381/17/10/302
published as Class.Quant.Grav. 17 (2000) 2059-2072 · 16 pages, epsfig latex. Some clarifications, minor corrections and references added. Version to appear in Classical and Quantum Gravity
arxiv created 2000/01/28 · arxiv updated 2009/11/30
Quantum causal histories are defined to be causal sets with Hilbert spaces attached to each event and local unitary evolution operators. The reflexivity, antisymmetry, and transitivity properties of a causal set are preserved in the quantum history as conditions on the evolution operators. A quantum causal history in which transitivity holds can be treated as ``directed'' topological quantum field theory. Two examples of such histories are described.