English
Related papers

Related papers: Quantum gravity and the problem of measurement

200 papers

Universal properties of entangled many-body states are controlled by their symmetry and quantum fluctuations. By magnetic-field tuning of the spin-orbital degeneracy in a Kondo-correlated quantum dot, we have modified quantum fluctuations…

Consider a scenario where $N$ separated quantum systems are measured, each with one among two possible dichotomic observables. Assume that the $N$ events corresponding to the choice and performance of the measurement in each site are…

Quantum Physics · Physics 2007-05-23 Ll. Masanes

We show how to use quantum metrology to detect a wormhole. A coherent state of the electromagnetic field experiences a phase shift with a slight dependence on the throat radius of a possible distant wormhole. We show that this tiny…

Quantum Physics · Physics 2017-04-07 Carlos Sabín

We construct an entanglement measure that coincides with the generalized concurrence for a general pure bipartite state based on wedge product. Moreover, we construct an entanglement measure for pure multi-qubit states, which are…

Quantum Physics · Physics 2007-05-23 Hoshang Heydari

We investigate different geometries and invariant measures on the space of mixed Gaussian quan- tum states. We show that when the global purity of the state is held fixed, these measures coincide and it is possible, within this constraint,…

Quantum Physics · Physics 2019-05-22 Philipp Sohr , Valentin Link , Kimmo Luoma , Walter T. Strunz

The quantification and classification of quantum entanglement is a very important and still open question of quantum information theory. In this paper, we describe an entanglement measure for multipartite pure states (the minimum of…

Quantum Physics · Physics 2009-05-05 A. Yu. Chernyavskiy

First a Friedmann-Robertson-Walker (FRW) universe filled with dust and a conformally invariant scalar field is quantized. For the closed model we find a discrete set of wormhole quantum states. In the case of flat spacelike sections we find…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Nivaldo A. Lemos , Flavio G. Alvarenga

We provide an affirmative answer to the question posed in the title. Our argument is based on a treatment of the Schroedinger dynamics of the composite of a quantum microsystem, S, and a macroscopic measuring apparatus, I, consisting of N…

Quantum Physics · Physics 2009-11-13 Geoffrey Sewell

Four-dimensional simplicial quantum gravity is modified either by coupling it to U(1) gauge fields or by introducing a measure weighted by the orders of the triangles. Strong coupling expansion and Monte Carlo simulations are used. Although…

High Energy Physics - Lattice · Physics 2009-10-31 S. Bilke , Z. Burda , A. Krzywicki , B. Petersson , J. Tabaczek , G. Thorleifsson

Utilizing the Hamiltonian constraints approach, a quantum-corrected solution has been derived \cite{Zhang:2024ney}, which describes either a regular black hole or a traversable wormhole, contingent upon the value of the quantum parameter.…

General Relativity and Quantum Cosmology · Physics 2025-05-30 R. A. Konoplya , O. S. Stashko

Despite the fact that we have some proposals for the quantum theory of gravity like string theory or loop quantum gravity, we do not have any experimental evidence supporting any of these theories. Actually, we do not have experimental…

Quantum Physics · Physics 2023-11-29 Thiago Henrique Moreira , Lucas Chibebe Céleri

We give an explicit axiomatic formulation of the quantum measurement theory which is free of the projection postulate. It is based on the generalized nondemolition principle applicable also to the unsharp, continuous-spectrum and…

Quantum Physics · Physics 2015-06-26 V. P. Belavkin

The Quantum Measurement Problem is arguably one of the most debated issues in the philosophy of Quantum Mechanics, since it represents not only a technical difficulty for the standard formulation of the theory, but also a source of…

Quantum Physics · Physics 2022-12-14 Andrea Oldofredi

We derive some of the central equations governing quantum fluctuations in gravitational waves, making use of general relativity as a sensible effective quantum theory at large distances. We begin with a review of classical gravitational…

General Relativity and Quantum Cosmology · Physics 2023-03-06 Mark P. Hertzberg , Jacob A. Litterer

Quantum gravity is extended to include purely virtual "cloud sectors", which allow us to define a complete set of point-dependent observables, including a gauge invariant metric and gauge invariant matter fields, and calculate their…

High Energy Physics - Theory · Physics 2023-11-22 Damiano Anselmi

An analysis of quantum measurement is presented that relies on an information-theoretic description of quantum entanglement. In a consistent quantum information theory of entanglement, entropies (uncertainties) conditional on measurement…

Quantum Physics · Physics 2008-02-03 N. J. Cerf , C. Adami

We propose a technical reformulation of the measurement problem of quantum mechanics, which is based on the postulate that the final state of a measurement is classical. Unlike the usual formulation (in which the post-measurement state is a…

Quantum Physics · Physics 2013-01-15 Klaas Landsman , Robin Reuvers

We explore the weak-field phenomenology of a compact star spacetime modified by quantum gravitational corrections derived from the effective field theoretical (EFT) approach by Calmet et al. [1]. These corrections, encoded in non-local…

General Relativity and Quantum Cosmology · Physics 2026-02-10 Reggie C. Pantig , Ali Ovgun , Gaetano Lambiase

The quantum decoherence program has become more attractive in providing an acceptable solution for the long-standing quantum measurement problem. Decoherence by quantum entanglement happens very quickly to entangle the quantum system with…

Popular Physics · Physics 2023-01-04 Mani L. Bhaumik

We give a simple demonstration that the Schr\"odinger equation may be recast as a self-contained second-order Newtonian law for a congruence of spacetime trajectories. This provides a pictorial representation of the quantum state as the…

Quantum Physics · Physics 2018-08-23 Peter Holland