English
Related papers

Related papers: The quantum phase problem: steps toward a resoluti…

200 papers

The "problem of time" in canonical quantum gravity refers to the difficulties involved in defining a Hilbert space structure on states -- and local observables on this Hilbert space -- for a theory in which the spacetime metric is treated…

General Relativity and Quantum Cosmology · Physics 2009-12-30 Robert M. Wald

Finite frame quantization is a discrete version of the coherent state quantization. In the case of a quantum system with finite-dimensional Hilbert space, the finite frame quantization allows us to associate a linear operator to each…

Quantum Physics · Physics 2022-07-18 Nicolae Cotfas

We study the structure of local algebras in relativistic conformal quantum field theory with phase boundaries. Phase boundaries are instances of a more general notion of boundaries that give rise to a variety of algebraic structures. These…

Mathematical Physics · Physics 2016-02-03 Marcel Bischoff , Yasuyuki Kawahigashi , Roberto Longo , Karl-Henning Rehren

Present day quantum field theory (QFT) is founded on canonical quantization, which has served quite well, but also has led to several issues. The free field describing a free particle (with no interaction term) can suddenly become…

General Physics · Physics 2021-08-13 John R. Klauder

State representations summarize our knowledge about a system. When unobservable quantities are introduced the state representation is typically no longer unique. However, this non-uniqueness does not affect subsequent inferences based on…

Quantum Physics · Physics 2009-11-10 Kae Nemoto , Samuel L. Braunstein

An adapted representation of quantum mechanics sheds new light on the relationship between quantum states and classical states. In this approach the space of quantum states splits into a product of the state space of classical mechanics and…

High Energy Physics - Theory · Physics 2021-04-14 Christoph Nölle

The classical phase of the matrix model of 11-dimensional M-theory is complex, infinite-dimensional Hilbert space. As a complex manifold, the latter admits a continuum of nonequivalent, complex-differentiable structures that can be placed…

Quantum Physics · Physics 2007-05-23 J. M. Isidro

A phase space formulation of the filtering process upon an incident quantum state is developed. This formulation can explain the results of both quantum interference and delayed-choice experiments without making use of the controversial…

Quantum Physics · Physics 2009-11-10 Daniela Dragoman

On a quantum particle in the unit interval $[0,1]$, perform a position measurement with inaccuracy $1/n$ and then a quantum measurement of the projection $|\phi\rangle\langle\phi|$ with some arbitrary but fixed normalized $\phi$. Call the…

Quantum Physics · Physics 2026-02-26 Xabier Oianguren-Asua , Roderich Tumulka

We discuss the question of entanglement versus separability of pure quantum states in direct product Hilbert spaces and the relevance of this issue to physics. Different types of separability may be possible, depending on the particular…

Quantum Physics · Physics 2009-11-07 Jon Eakins , George Jaroszkiewicz

We point out the crucial difference between the relative and absolute phase observables treated in our contribution \cite{1} and in the Comment by Hall and Pegg \cite{HP} respectively. The main contribution of our work is to show that the…

Quantum Physics · Physics 2012-11-16 D. Aesenovic , N. Buric , D. Davidovic , S. Prvanovic

It has recently been argued that the inability to measure the absolute phase of an electromagnetic field prohibits the representation of a laser's output as a quantum optical coherent state. This argument has generally been considered…

Quantum Physics · Physics 2009-11-10 Kae Nemoto , Samuel L. Braunstein

We study various ways of characterising the quantum optical number and phase as complementary observables.

Quantum Physics · Physics 2009-11-07 Paul Busch , Pekka Lahti , Juha-Pekka Pellonpaa , Kari Ylinen

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

A fundamental problem with attempting to quantize general relativity is its perturbative non-renormalizability. However, this fact does not rule out the possibility that non-perturbative effects can be computed, at least in some…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Viqar Husain , Sebastian Jaimungal

In certain circumstances, the uncertainty, $\Delta S [\phi]$, of a quantum observable, $S$, can be bounded from below by a finite overall constant $\Delta S>0$, \emph{i.e.}, $\Delta S [\phi] \geq \Delta S$, for all physical states $\phi$.…

Quantum Physics · Physics 2015-08-25 R. T. W. Martin , A. Kempf

Mathematical method of quantum phase space is very useful in physical applications like quantum optics and non-relativistic quantum mechanics. However, attempts to generalize it for the relativistic case lead to some difficulties. One of…

Quantum Physics · Physics 2008-11-26 A. A. Semenov , B. I. Lev , C. V. Usenko

Building on earlier work, we further develop a formalism based on the mathematical theory of frames that defines a set of possible phase-space or quasi-probability representations of finite-dimensional quantum systems. We prove that an…

Quantum Physics · Physics 2009-06-23 Christopher Ferrie , Joseph Emerson

We give a review of concepts related to connection of classical and quantum theories, from the phase space perspective. Quantum theory is described by non-commutative operators of coordinates and momenta, results in values having a certain…

Quantum Physics · Physics 2025-09-04 Miloš D. Davidović , Ljubica D. Davidović , Milena D. Davidović

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