# Classical and quantum cosmology with York time

@article{Roser2014ClassicalAQ, title={Classical and quantum cosmology with York time}, author={Philipp Roser and Antony Valentini}, journal={Classical and Quantum Gravity}, year={2014}, volume={31} }

We consider a solution to the problem of time in quantum gravity by deparameterization of the ADM action in terms of York time, a parameter proportional to the extrinsic curvature of a spatial hypersurface. We study a minisuperspace model together with a homogeneous scalar field, for which we can solve the Hamiltonian constraint exactly and arrive at an explicit expression for the physical (non-vanishing) Hamiltonian. The scale factor and associated momentum cease to be dynamical variables…

## 20 Citations

Quantum mechanics on York slices

- Physics
- 2015

For some time the York time parameter has been identified as a candidate for a physically meaningful time in cosmology. An associated Hamiltonian may be found by solving the Hamiltonian constraint…

Trans-Planckian fluctuations and the stability of quantum mechanics

- Physics
- 2014

We present arguments suggesting that deviations from the Born probability rule could be generated for trans-Planckian field modes during inflation. Such deviations are theoretically possible in the…

Semiclassical momentum representation in quantum cosmology

- Computer Science, Physics
- 2016

A new class of semiclassical solutions of the Wheeler-deWitt equation using the conjugate momentum to the geometric variable is obtained, and it is shown that the momentum representation possesses many advantages that are absent in other apporaches.

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- 2021

We argue that in quantum gravity there is no Born rule. The quantumgravity regime, described by a non-normalisable Wheeler-DeWitt wave functional Ψ, must be in quantum nonequilibrium with a…

Quantum-classical correspondence for the inverted oscillator

- Physics
- 2017

While quantum-classical correspondence for a system is a very fundamental problem in modern physics, the understanding of its mechanism is often elusive, so the methods used and the results of…

Intrinsic time in Wheeler–DeWitt conformal superspace

- Physics, Mathematics
- 2017

Intrinsic time in geometrodynamics is obtained using a scaled Dirac mapping. By addition of a background metric, one can construct a scalar field which is suitable for the role of intrinsic time. The…

Intrinsic time in Wheeler-DeWitt conformal superspace

- Physics
- 2015

An intrinsic time in Geometrodynamics is obtained with using a scaled Dirac's mapping. By addition of a background metric, one can construct a scalar field. It is suitable to play a role of intrinsic…

On Generalised Statistical Equilibrium and Discrete Quantum Gravity

- PhysicsSpringer Theses
- 2022

Statistical equilibrium configurations are important in the physics of macroscopic systems with a large number of constituent degrees of freedom. They are expected to be crucial also in discrete…

An extension of cosmological dynamics with York time

- Physics
- 2014

It has been suggested that the York parameter T (effectively the scalar extrinsic curvature of a spatial hypersurface) may play the role of a fundamental time parameter. In a flat, forever expanding…

2 9 M ay 2 01 6 Intrinsic time in Wheeler – DeWitt conformal superspace

- Physics
- 2018

An intrinsic time in Geometrodynamics is obtained with using a scaled Dirac’s mapping. By addition of a background metric, one can construct a scalar field. It is suitable to play a role of intrinsic…

## References

SHOWING 1-10 OF 39 REFERENCES

Dust as a standard of space and time in canonical quantum gravity.

- PhysicsPhysical review. D, Particles and fields
- 1995

The particles of dust introduce into space a privileged system of coordinates that allows the supermomentum constraint to be solved explicitly and yields a formally conserved inner product that can be written in terms of either the instantaneous state functionals or the solutions of constraints.

Modern Canonical Quantum General Relativity

- Physics
- 2007

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…

Inflationary Cosmology as a Probe of Primordial Quantum Mechanics

- Physics
- 2010

We show that inflationary cosmology may be used to test the statistical predictions of quantum theory at very short distances and at very early times. Hidden-variables theories, such as the…

Einstein gravity as a 3D conformally invariant theory

- Mathematics, Physics
- 2011

We give an alternative description of the physical content of general relativity that does not require a Lorentz invariant spacetime. Instead, we find that gravity admits a dual description in terms…

Time and a physical Hamiltonian for quantum gravity.

- PhysicsPhysical review letters
- 2012

A nonperturbative quantization of general relativity coupled to dust, leading to a physical Hamiltonian with spatial diffeomorphism symmetry that provides a complete theory of quantum gravity and puts applications to cosmology, quantum gravitational collapse, and Hawking radiation within technical reach.

Scale-invariant gravity: geometrodynamics

- Physics
- 2003

We present a scale-invariant theory, conformal gravity, which closely resembles the geometrodynamical formulation of general relativity (GR). While previous attempts to create scale-invariant…

The physical gravitational degrees of freedom

- Physics
- 2005

When constructing general relativity (GR), Einstein required 4D general covariance. In contrast, we derive GR (in the compact, without boundary case) as a theory of evolving three-dimensional…

Quantum-to-classical transition of primordial cosmological perturbations in de Broglie–Bohm quantum theory

- Physics, Philosophy
- 2012

There is a widespread belief that the classical small inhomogeneities which gave rise to all structures in the Universe through gravitational instability originated from primordial quantum…

Problem of time in quantum gravity

- Physics
- 2010

The Problem of Time occurs because the ‘time’ of GR and of ordinary Quantum Theory are mutually incompatible notions. This is problematic in trying to replace these two branches of physics with a…

Quantum-to-classical transition of primordial cosmological perturbations in de Broglie-Bohm quantum theory: the bouncing scenario

- Physics
- 2014

In a previous work we have exhibited a clear description of the quantum-to-classical transition of cosmological quantum fluctuations in the inflationary scenario using the de Broglie-Bohm quantum…