English
Related papers

Related papers: Semiclassical states for quantum cosmology

200 papers

Symmetric states are defined in the kinematical sector of loop quantum gravity and applied to spherical symmetry and homogeneity. Consequences for the physics of black holes and cosmology are discussed.

General Relativity and Quantum Cosmology · Physics 2017-08-23 M. Bojowald , H. A. Kastrup

A simple position probability density formulation is presented for the motion of a particle in a spherically symmetric potential. The approach provides an alternative to Newtonian methods for presentation in an elementary course, and…

Physics Education · Physics 2007-05-23 Lorenzo J. Curtis , David G. Ellis

Quantum machine learning (QML) seeks to exploit the intrinsic properties of quantum mechanical systems, including superposition, coherence, and quantum entanglement for classical data processing. However, due to the exponential growth of…

Quantum Physics · Physics 2025-10-09 Timothy Heightman , Edward Jiang , Ruth Mora-Soto , Maciej Lewenstein , Marcin Płodzień

Developments in theoretical cosmology in the recent decades show a close connection with particle physics, quantum gravity and unified theories. Answers or hints to many fundamental questions in cosmology like the homogeneity and isotropy…

General Relativity and Quantum Cosmology · Physics 2007-05-23 B. L. Hu

The formalism of classical and quantum mechanics on phase space leads to symplectic and Heisenberg group representations, respectively. The Wigner functions give a representation of the quantum system using classical variables. The…

Quantum Physics · Physics 2007-05-23 Ajay Patwardhan

The formalism to treat quantization and evolution of cosmological perturbations of multiple fluids is described. We first construct the Lagrangian for both the gravitational and matter parts, providing the necessary relevant variables and…

General Relativity and Quantum Cosmology · Physics 2016-02-01 Patrick Peter , Nelson Pinto-Neto , Sandro Dias Pinto Vitenti

The pure state space of Quantum Mechanics is investigated as Hermitian Symmetric Kaehler manifold. The classical principles of Quantum Mechanics (Quantum Superposition Principle, Heisenberg Uncertainty Principle, Quantum Probability…

Quantum Physics · Physics 2009-11-07 R. Cirelli , M. Gatti , A. Maniá

The probability representation, in which cosmological quantum states are described by a standard positive probability distribution, is constructed for minisuperspace models selected by Noether symmetries. In such a case, the tomographic…

General Relativity and Quantum Cosmology · Physics 2008-12-18 S. Capozziello , V. I. Man'ko , G. Marmo , C. Stornaiolo

Based on a more careful canonical analysis, we motivate a reduced quantization - in the sense of superspace quantization - of slightly inhomogeneous cosmology in place of the Dirac quantization in the existing literature, and provide it in…

General Relativity and Quantum Cosmology · Physics 2016-04-05 Edward Anderson

We show how nonrelativistic many body techniques can be used to study quantum corrections to the classical limit, in particular of the $SU(2)$ Lipkin Model. We show that the quantum corrections are essentially of two types: unitary and…

Quantum Physics · Physics 2008-02-03 M. Trindade dos Santos , M. C. Nemes

The theory of quantum fields propagating on an isotropic cosmological quantum spacetime is reexamined by generalizing the scalar test field to an electromagnetic (EM) vector field. For any given polarization of the EM field on the classical…

General Relativity and Quantum Cosmology · Physics 2017-11-15 Jerzy Lewandowski , Mohammad Nouri-Zonoz , Ali Parvizi , Yaser Tavakoli

Identifying the real and imaginary parts of wave functions with coordinates and momenta, quantum evolution may be mapped onto a classical Hamiltonian system. In addition to the symplectic form, quantum mechanics also has a positive-definite…

Quantum Physics · Physics 2009-11-07 R. Vilela Mendes , V. I. Man'ko

We construct a macroscopic semiclassical state state for a quantum tetrahedron. The expectation values of the geometrical operators representing the volume, areas and dihedral angles are peaked around assigned classical values, with…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Carlo Rovelli , Simone Speziale

A discussion is given of the quantisation of a physical system with finite degrees of freedom subject to a Hamiltonian constraint by treating time as a constrained classical variable interacting with an unconstrained quantum state. This…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Charles Wang

A two-mode optical parity-time (PT) symmetric system, with gain and damping, described by a quantum quadratic Hamiltonian with additional small Kerr-like nonlinear terms, is analyzed from the point of view of nonclassical-light generation.…

Quantum Physics · Physics 2019-11-14 Jan Perina , Antonin Luks , Joanna K. Kalaga , Wieslaw Leonski , Adam Miranowicz

Non-classical probability (along with its underlying logic) is a defining feature of quantum mechanics. A formulation that incorporates them, inherently and directly, would promise a unified description of seemingly different prescriptions…

Quantum Physics · Physics 2019-05-21 Soumik Adhikary , Sooryansh Asthana , V. Ravishankar

One of the most central and controversial element of quantum mechanics is the use of non zero vectors of a Hilbert space (or, more generally, of one dimension subspaces) for representing the state of a quantum system. In particular, the…

Quantum Physics · Physics 2009-11-13 Olivier Brunet

The interrelation between classicality/quantumness and symmetry of states is discussed within the phase-space formulation of finite-dimensional quantum systems. We derive representations for classicality measures…

Quantum Physics · Physics 2023-12-12 Arsen Khvedelidze , Astghik Torosyan

In this paper, we investigate the connection between Classical and Quantum Mechanics by dividing Quantum Theory in two parts: - General Quantum Axiomatics (a system is described by a state in a Hilbert space, observables are self-adjoint…

Quantum Physics · Physics 2009-11-07 H. Bergeron

We introduce a class of space-times modeling singular events such as evaporating black holes and topology changes, which we dub as semi-globally hyperbolic space-times. On these space-times we aim to study the existence of reasonable…

General Relativity and Quantum Cosmology · Physics 2022-05-23 Daan Willem Janssen