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Related papers: Quantum gravity and the problem of measurement

200 papers

We propose an energy-driven stochastic master equation for the density matrix as a dynamical model for quantum state reduction. In contrast, most previous studies of state reduction have considered stochastic extensions of the Schr\"odinger…

Quantum Physics · Physics 2016-12-30 Dorje C. Brody , Lane P. Hughston

A model of matter-coupled gravity in two dimensions is quantized. The crucial requirement for performing the quantization is the vanishing of the conformal anomaly, which is achieved by tuning a parameter in the interaction potential. The…

High Energy Physics - Theory · Physics 2009-11-07 M. Cadoni , P. Carta , S. Mignemi

The question of a possibility of opening a wormhole due to the deformation of the equation of state of the matter caused by quantum gravity effects is considered. As a wormhole environment, the previously considered model of a galaxy with…

General Physics · Physics 2021-02-23 Igor Nikitin

Semiclassical gravity couples classical gravity to the quantized matter in meanfield approximation. The meanfield coupling is problematic for two reasons. First, it ignores the quantum fluctuation of matter distribution. Second, it violates…

General Relativity and Quantum Cosmology · Physics 2025-05-28 Lajos Diósi

We quantize the two-dimensional projectable Horava-Lifshitz gravity with a bi-local as well as space-like wormhole interaction. The resulting quantum Hamiltonian coincides with the one obtained through summing over all genus in the string…

High Energy Physics - Theory · Physics 2021-03-17 Jan Ambjorn , Yuki Hiraga , Yoshiyasu Ito , Yuki Sato

We discuss the relevance of quantum gravity to the frontier questions in high energy phenomenology: the problems of dark matter, dark energy, and vacuum selection as well as the problems of emergent spacetime and wormholes. Dark matter and…

We show that in a two-dimensional model of quantum gravity the summation over all possible wormhole configurations leads to a kind of Coleman mechanism where the cosmological constant plays no role for large universes. Observers who are…

High Energy Physics - Theory · Physics 2021-02-24 Jan Ambjorn , Yuki Sato , Yoshiyuki Watabiki

This work is originally a Cambridge Part III essay paper. Quantum complexity arises as an alternative measure to the Fubini metric between two quantum states. Given two states and a set of allowed gates, it is defined as the least complex…

Quantum Physics · Physics 2021-04-13 Andrea Russo

The transition from classical to quantum mechanics rests on the recognition that the structure of information is not what we thought it was: there are operational, i.e., phenomenal, probabilistic correlations that lie outside the polytope…

Quantum Physics · Physics 2015-06-11 Jeffrey Bub

The notion of state vector is, in quantum mechanics, as central as it is problematic, as illustrates the wealth of publications about the sub- jects, including in particular the many attempts to obtain an acceptable interpretation of…

Quantum Physics · Physics 2013-05-07 Olivier Brunet

The weak measurement (WM) and quantum measurement reversal (QMR) are crucial in protecting the collapse of quantum states. The idea of WM and QMR has recently been used to protect and enhance quantum correlations and universal quantum…

Quantum Physics · Physics 2025-09-03 Jai Lalita , Subhashish Banerjee

We study a system of two pointlike particles coupled to three dimensional Einstein gravity. The reduced phase space can be considered as a deformed version of the phase space of two special-relativistic point particles in the centre of mass…

General Relativity and Quantum Cosmology · Physics 2010-05-28 Jorma Louko , Hans-Juergen Matschull

Vielbeins are necessary when coupling General Relativity (GR) to fermionic matter. This enhances the gauge group of GR to include local Lorentz transformations. In view of a reduced phase space formulation of quantum gravity, in this work…

General Relativity and Quantum Cosmology · Physics 2023-05-12 Thomas Thiemann

Entanglement of any pure state of an N times N bi-partite quantum system may be characterized by the vector of coefficients arising by its Schmidt decomposition. We analyze various measures of entanglement derived from the generalized…

Quantum Physics · Physics 2009-11-07 Karol Zyczkowski , Ingemar Bengtsson

We propose and simulate a protocol to evolve a quantum particle forward in time such that its trajectory closely matches that of the particle's Newtonian counterpart. Using short bursts of Schr\"odinger time-evolution interleaved with…

Quantum Physics · Physics 2025-10-21 Youheng Zheng

We outline, test, and apply a new scheme for nonpertubative analyses of quantized field systems in contact with dynamical gravity. While gravity is treated classically in the present paper, the approach lends itself for a generalization to…

General Relativity and Quantum Cosmology · Physics 2020-12-30 Maximilian Becker , Martin Reuter

We study the $N \times N$ Hermitian one-matrix model modified by the double-trace interaction. It is known that the coupling for the double-trace interaction can control the weight for the microscopic wormholes if interpreting the matrix…

High Energy Physics - Theory · Physics 2025-06-02 Tsunehide Kuroki , Yuki Sato

An exploratory approach to the possibility of analyzing nonorthogonality as a quantifiable property is presented. Three different measures for the nonorthogonality of pure states are introduced, and one of these measures is extended to…

Quantum Physics · Physics 2009-10-31 Oliver Cohen

Experimentally observed violations of Bell inequalities rule out local realistic theories. Consequently, the quantum state vector becomes a strong candidate for providing an objective picture of reality. However, such an ontological view of…

Quantum Physics · Physics 2007-05-23 Bernd A. Berg

The purpose of this work is to investigate the consequences of quantum gravity for the singularity problem. We study the higher-derivative terms that invariably appear in any quantum field theoretical model of gravity, handling them both…

High Energy Physics - Theory · Physics 2020-01-22 Iberê Kuntz , Roberto Casadio