University of California, San Diego

Project Title

Time in Quantum Causal Set Histories

Project Summary

Einstein's theory of gravity, General Relativity, and our theory which governs the sub-atomic world, Quantum Theory, give seemingly inconsistent accounts of the nature of time. According to General Relativity, each observer will have a separate notion of time, based upon his or her 'tra jectory' within the spacetime history of the universe. According to Quantum Theory, there is only one notion of time which govern the evolution of physical systems. The inconsistency leads to considerable problems when attempting to write down a theory which incorporates both gravity and the quantum. The 'histories formulation' of Quantum Theory, as pioneered by Feynman, provides a potential resolution to this conundrum, by allowing a formulation of quantum theory in which time plays the same role as in General Relativity. Historically Feynman's formulation has been regarded more as a calculational tool than a genuine interpretive framework for Quantum Theory. Additionally it brings a multitude of mathematical complications, which makes progress in this direction difficult. We propose to sidestep the mathematical complications by assuming that the universe is composed of an enormous number of tiny discrete elements, and asking whether the resulting quantum theory of cosmology can produce universes which resemble our own.

Back to List of Awardees