English

Covariant canonical quantization and the problem of time

General Relativity and Quantum Cosmology 2023-12-25 v2 High Energy Physics - Theory

Abstract

In the covariant canonical approach to classical physics, each point in phase space represents an entire classical trajectory. Initial data at a fixed time serve as coordinates for this ``timeless'' phase space, and time evolution can be viewed as a coordinate change. We argue for a similar view in quantum theory. As in the Heisenberg picture, the wave function is fundamentally time-independent. On any given time slice, however, we can diagonalize a complete set of position operators to form a basis, in which the projected wave function depends on the choice of time. In this picture, time evolution can be viewed as a basis change in what is otherwise a block universe. We argue that this may help solve the ``problem of time'' in quantum gravity, and illustrate the idea with an example from three-dimensional quantum gravity.

Keywords

Cite

@article{arxiv.2312.10272,
  title  = {Covariant canonical quantization and the problem of time},
  author = {S. Carlip and Weixuan Hu},
  journal= {arXiv preprint arXiv:2312.10272},
  year   = {2023}
}

Comments

contribution to the book "Time and timelessness in fundamental physics and cosmology," edited by Silvia De Bianchi, Marco Forgione and Laura Marongiu , to be published by Springer; v2: eqn (3.1) corrected (commutators in covariant phase space), no change in conclusions

R2 v1 2026-06-28T13:53:14.734Z