RECORD
A Cosmological Sector in Loop Quantum Gravity
General Relativity and Quantum Cosmology · Submitted 7 Nov 2007
abstract compiled · 2026-09-23 · no language-model review
The authors' main claim The full operator algebra however turns out to be different from standard Loop Quantum Cosmology.
The compiled record
The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
Open the compiled record
The abstract, sentence by sentence
We use the method of embedding a subsystem (i.e. its observable algebra) into a larger quantum system to extract a cosmological sector from full Loop Quantum Gravity. The application of this method provides a setting for a systematic study of the interplay between diffeomorphism invariance and symmetry reduction. The non-triviality of this relation is shown by extracting a cosmological system that has configurations variables that are very similar to the ones of a super-selection sector of standard Loop Quantum Cosmology. The full operator algebra however turns out to be different from standard Loop Quantum Cosmology. The homogeneous isotropic sector of pure gravity turns out to be quantum mechanics on a circle. The dynamics of our system seems pathological at first sight, and we give both mathematical and physical reasons for this behavior and we explain a strategy to cure these pathologies.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We use the method of embedding a subsystem (i.e. its observable algebra) into a larger quantum system to extract a cosmological sector from full Loop Quantum Gravity. | method 0.96 | 0.95 | 0.09 | asserted 1.00 |
| s1 | The application of this method provides a setting for a systematic study of the interplay between diffeomorphism invariance and symmetry reduction. | contribution 0.62 | 0.71 | 0.08 | asserted 0.94 |
| s2 | The non-triviality of this relation is shown by extracting a cosmological system that has configurations variables that are very similar to the ones of a super-selection sector of standard Loop Quantum Cosmology. | result 0.95 | 0.93 | 0.24 | asserted 1.00 |
| s3 | The full operator algebra however turns out to be different from standard Loop Quantum Cosmology. | result 1.00 | 0.93 | 0.22 | asserted 1.00 |
| s4 | The homogeneous isotropic sector of pure gravity turns out to be quantum mechanics on a circle. | result 1.00 | 0.93 | 0.19 | asserted 0.99 |
| s5 | The dynamics of our system seems pathological at first sight, and we give both mathematical and physical reasons for this behavior and we explain a strategy to cure these pathologies. | result 0.50 | 0.93 | 0.14 | hedged possibility 0.78 |
What was examined, and what was not
- arXiv listing abstract v1
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
The paper
Original abstract
We use the method of embedding a subsystem (i.e. its observable algebra) into a larger quantum system to extract a cosmological sector from full Loop Quantum Gravity. The application of this method provides a setting for a systematic study of the interplay between diffeomorphism invariance and symmetry reduction. The non-triviality of this relation is shown by extracting a cosmological system that has configurations variables that are very similar to the ones of a super-selection sector of standard Loop Quantum Cosmology. The full operator algebra however turns out to be different from standard Loop Quantum Cosmology. The homogeneous isotropic sector of pure gravity turns out to be quantum mechanics on a circle. The dynamics of our system seems pathological at first sight, and we give both mathematical and physical reasons for this behavior and we explain a strategy to cure these pathologies.
Human review
References
How the literature uses it
8 arXiv papers cite this in 8 sentences
Papers citing it · 7 sentences without a confident label
Cites it as background 1 paper
-
However, the relation between LQC and full LQG is still an open question, given that to date, there is no precise way of deriving the homogeneous theory from the full theory (however, see [ref] for recent attempts).
Is loop quantization in cosmology unique? · Introduction · 0.82
What it cites · 23 sentences without a confident label
Uses the method or tool of 2 papers
-
Given a particular gauge fixing for the diffeomorphisms, we can apply the techniques of [ref] to construct a cosmological sector of Loop Quantum Gravity.
Reduction of a Quantum Theory · Strategy · 0.99
-
We will work with an adaption of the Weyl-algebra setting for LQG [ref] in this paper, which allows us to work in the the $C^*$-algebraic framework.
Energy conditions outside a dielectric ball · Introduction · 0.98
Compares with 2 papers
-
We have already mentioned differences between our approach outlined in this paper and Loop Quantum Cosmology as it is presented by [ref] .
Mathematical structure of loop quantum cosmology · Comparison with Standard Loop Quantum Cosmology · 0.99
-
The resulting isotropic model would be similar to [ref] , which has the Bohr compactification of $ℝ$ as its quantum configuration space.
Comments on the kinematical structure of loop quantum cosmology · Comments about the Embedding Maps · 0.91
Cites as background 2 papers
-
A successful theory of quantum gravity is provided by Loop Quantum Gravity (LQG) [ref] which has sparked investigations into Loop Quantum Cosmology (LQC) premiered by Bojowald [ref] .
Oscillatory approach to the singularity in vacuum $T^2$ symmetric spacetimes · Introduction · 1.00
-
The states of LQC need a physical interpretation and is not induced by the relation of Loop Quantum Cosmology and Loop Quantum Gravity itself; see [ref] for a discussion of the physical interpretation of the states of Loop Quantum Cosmology.
Relating loop quantum cosmology to loop quantum gravity: Symmetric sectors and embeddings · Treatment of Observables and States · 0.87
Discussion
Know something about this paper? Leave a comment, or highlight any passage above to comment on it.