# Canonical quantum gravity and the problem of time

@inproceedings{Isham1992CanonicalQG, title={Canonical quantum gravity and the problem of time}, author={Christopher John Isham}, year={1992} }

The aim of this paper is to provide a general introduction to the problem of time in quantum gravity. This problem originates in the fundamental conflict between the way the concept of ‘time’ is used in quantum theory, and the role it plays in a diffeomorphism-invariant theory like general relativity. Schemes for resolving this problem can be sub-divided into three main categories: (I) approaches in which time is identified before quantising; (II) approaches in which time is identified after…

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