A Fundamental Problem in Quantizing General Relativity

@article{Maccone2019AFP,
  title={A Fundamental Problem in Quantizing General Relativity},
  author={Lorenzo Maccone},
  journal={Foundations of Physics},
  year={2019}
}
  • L. Maccone
  • Published 3 July 2018
  • Physics
  • Foundations of Physics
We point out a fundamental problem that hinders the quantization of general relativity: quantum mechanics is formulated in terms of systems, typically limited in space but infinitely extended in time, while general relativity is formulated in terms of events, limited both in space and in time. Many of the problems faced while connecting the two theories stem from the difficulty in shoe-horning one formulation into the other. A solution is not presented, but a list of desiderata for a quantum… 
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References

SHOWING 1-10 OF 89 REFERENCES
Canonical quantum gravity and the problem of time
The aim of this paper is to provide a general introduction to the problem of time in quantum gravity. This problem originates in the fundamental conflict between the way the concept of ‘time’ is used…
Quantum Interference in Time
I discuss the interpretation of a recent experiment showing quantum interference in time. It is pointed out that the standard nonrelativistic quantum theory does not have the property of coherence in…
Quantum gravity: a quantum-first approach
A "quantum-first" approach to gravity is described, where rather than quantizing general relativity, one seeks to formulate the physics of gravity within a quantum-mechanical framework with suitably…
Conceptual Problems Related to Time and Mass in Quantum Theory
The concept of proper time cannot be just taken over from classical theory and applied to quantum theory. There are a number of serious ambiguities related to it. Similarly, the concept of mass has…
The Madelung Picture as a Foundation of Geometric Quantum Theory
Despite its age, quantum theory still suffers from serious conceptual difficulties. To create clarity, mathematical physicists have been attempting to formulate quantum theory geometrically and to…
Quantum-First Gravity
This paper elaborates on an intrinsically quantum approach to gravity, which begins with a general framework for quantum mechanics and then seeks to identify additional mathematical structure on…
Operational quantum theory without predefined time
The standard formulation of quantum theory assumes a predefined notion of time. This is a major obstacle in the search for a quantum theory of gravity, where the causal structure of space-time is…
Quantum Fields in Curved Space
This book presents a comprehensive review of the subject of gravitational effects in quantum field theory. Although the treatment is general, special emphasis is given to the Hawking black hole…
An introduction to quantum gravity
Quantum gravity was born as that branch of modern theoretical physics that tries to unify its guiding principles, i.e., quantum mechanics and general relativity. Nowadays it is providing new insight…
Quantum mechanics near closed timelike lines.
  • Deutsch
  • Physics
    Physical review. D, Particles and fields
  • 1991
TLDR
Several novel and distinctive quantum-mechanical effects occur on and near closed timelike lines, including violations of the correspondence principle and of unitarity, and consideration of these sheds light on the nature of quantum mechanics.
...
...