Positive energy in quantum gravity

@article{Smolin2014PositiveEI,
  title={Positive energy in quantum gravity},
  author={Lee Smolin},
  journal={Physical Review D},
  year={2014},
  volume={90},
  pages={044034}
}
  • L. Smolin
  • Published 10 June 2014
  • Physics
  • Physical Review D
This paper addresses the question of whether Witten’s proof of positive ADM energy for classical general relativity[3] can be extended to give a proof of positive energy for a non-perturbative quantization of general relativity. To address this question, a set of conditions is shown to be sufficient for showing the positivity of a Hamiltonianoperatorcorrespondingto theADM energy. One oftheseconditions is a particular factor ordering for the constraints of general relativity, in a representation… 

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References

SHOWING 1-10 OF 13 REFERENCES

Lectures on Non-Perturbative Canonical Gravity

Notes prepared in Collaboration with Ranjeet S Tate It is now generally recognized that perturbative field theoretical methods that have been highly successful in the quantum description of

Loop quantum gravity vacuum with nondegenerate geometry

In loop quantum gravity, states of the gravitational field turn out to be excita- tions over a vacuum state that is sharply peaked on a degenerate spatial geometry. While this vacuum is singled out

On loop quantum gravity kinematics with a non-degenerate spatial background

In a remarkable paper (Koslowski T A 2007 arXiv:0709.3465[gr-qc]), Koslowski introduced kinematical representations for loop quantum gravity in which a non-degenerate spatial background metric is

A new vacuum for loop quantum gravity

We construct a new vacuum and representation for loop quantum gravity. Because the new vacuum is based on BF theory, it is physical for (2+1)-dimensional gravity, and much closer to the spirit of

Modern Canonical Quantum General Relativity

This is an introduction to the by now fifteen years old research field of canonical quantum general relativity, sometimes called "loop quantum gravity". The term "modern" in the title refers to the

New variables for canonical supergravity

Ashtekar's reformulation (1987) of canonical general relativity is extended to simple supergravity in four dimensions. The key idea is to use the left-handed spin connection as a complex coordinate

Recent Developments in Non-Perturbative Quantum Gravity

New results from the new variables/loop representation program of nonperturbative quantum gravity are presented, with a focus on results of Ashtekar, Rovelli and the author which greatly clarify the

Dynamical Quantum Geometry (DQG Programme)

In this brief note (written as a lengthy letter), we describe the construction of a representation for the Weyl-algebra underlying Loop Quantum Geometry constructed from a diffeomorphism variant

Quantum Spin Dynamics (QSD)

An anomaly-free operator corresponding to the Wheeler - DeWitt constraint of Lorentzian, four-dimensional, canonical, non-perturbative vacuum gravity is constructed in the continuum. This operator is

The Koslowski–Sahlmann representation: quantum configuration space

The Koslowski–Sahlmann (KS) representation is a generalization of the representation underlying the discrete spatial geometry of loop quantum gravity (LQG), to accommodate states labelled by smooth