Where to Apply Relationalism
arXiv:1411.4316
Abstract
Relationalism -- along the lines developed by Barbour and collaborators in the past 3 decades -- can be considered an advance with 1/4 of the facets of the canonical approach's Problem of Time as identified by Isham and Kuchar. Indeed, almost all of the Problem of Time facets have classical counterparts, since they arise from consequences of demanding background independence rather than about combining GR and QM per se. Moreover the quantum version is harder, while the classical counterpart provides some suggestions through being more solvable. The suggestion then is to consider the effect of this advance on the Problem of Time as a whole, as opposed to repeating the same classical portion for a different redundancy group acting on the configuration space: shape dynamics. There are indeed some knock-on effects because the facets are notoriously not independent. The other facets do also however require distinct insights. Finally, I comment on the above being `metric' background independence, whereas quantum gravity usually assumes many other levels of background structures. Whilst Isham already wrote about this over two decades ago, it has largely not yet been incorporated into quantum gravity programs, and could well be a good area to extend and re-envigour by use of relational thinking.
24 pages including 9 figures. Comments and references updated. arXiv admin note: substantial text overlap with arXiv:1409.4117
References in corpus (24)
- The Dynamics of General Relativity
- Problem of Time in Quantum Gravity
- Some remarks on the notions of general covariance and background independence
- Continuous Histories and the History Group in Generalised Quantum Theory
- The Problem of Time in Quantum Gravity
- The Link between General Relativity and Shape Dynamics
- Somewhere in the Universe: Where is the Information Stored When Histories Decohere?
- The Problem of Time and Quantum Cosmology in the Relational Particle Mechanics Arena
- Probabilities in Quantum Cosmological Models: A Decoherent Histories Analysis Using a Complex Potential
- Beables/Observables in Classical and Quantum Gravity
- A Shape Dynamics Tutorial
- Problem of Time and Background Independence: the Individual Facets
- New interpretation of variational principles for gauge theories. I. Cyclic coordinate alternative to ADM split
- Conformal Superspace: the configuration space of general relativity
- Classical Machian Resolution of the Spacetime Reconstruction Problem
- Approaching the Problem of Time with a Combined Semiclassical-Records-Histories Scheme
- Machian Time Is To Be Abstracted From What Change?
- On Background Independence
- TRiPoD (Temporal Relationalism incorporating Principles of Dynamics)
- Kendall's Shape Statistics as a Classical Realization of Barbour-type Timeless Records Theory approach to Quantum Gravity
- Origin of Structure in the Universe: Quantum Cosmology Reconsidered
- Problem of Time: Facets and Machian Strategy
- Lorentz Invariance in Shape Dynamics
- 'Shape Dynamics': Foundations Reassessed