Timeline for If quantum gravity is a TQFT, why isn't the Wheeler-De Witt equation satisfied automatically?
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10 events
| when toggle format | what | by | license | comment | |
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| Sep 5, 2022 at 15:51 | vote | accept | nodumbquestions | ||
| Jun 6, 2022 at 12:00 | comment | added | Xenomorph | The canonical hamiltonian being zero is imposed as a constraint on the phase space. It's like the Gauss-law $\nabla\cdot\vec{E}=0$ in QED and QCD. Physical states should be gauge invariant, i.e $\nabla\cdot\vec{E}|\psi\rangle=0$. The Wheeler-de Witt equation you wrote is like the "Gauss-law" for diffeomorphism. | |
| May 13, 2022 at 12:11 | answer | added | nodumbquestions | timeline score: 0 | |
| Mar 31, 2022 at 14:21 | answer | added | ACuriousMind♦ | timeline score: 2 | |
| Mar 31, 2022 at 13:10 | comment | added | nodumbquestions | @AccidentalFourierTransform What do you mean by "on-shell". I've only previously seen that term used to describe classical trajectories, in which case it means those which make the action stationary. But in my question, $H$ acts on kets labelled by "geometry on a slice", and I don't know what it means for geometry on a single slice to be "on-shell". | |
| Mar 31, 2022 at 13:06 | comment | added | nodumbquestions | @Qmechanic see e.g first para of arxiv.org/abs/gr-qc/9506070 | |
| Mar 31, 2022 at 12:20 | comment | added | AccidentalFourierTransform | The Hamiltonian of TQFTs does not usually vanish identically. Your argument only shows that it vanishes on-shell, and indeed $H$ is almost always non-trivial, but proportional to constraints. Check the canonical quantization of Chern-Simons theories, for example. | |
| Mar 31, 2022 at 11:58 | history | edited | Qmechanic♦ | CC BY-SA 4.0 |
added 4 characters in body
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| Mar 31, 2022 at 11:58 | comment | added | Qmechanic♦ | Often said where? Which page? | |
| Mar 31, 2022 at 11:00 | history | asked | nodumbquestions | CC BY-SA 4.0 |