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Related papers: Operator ordering and causality

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A brief overview of some open questions in general relativity with important consequences for causality theory is presented, aiming to a better understanding of the causal structure of the spacetime. Special attention is accorded to the…

General Relativity and Quantum Cosmology · Physics 2016-01-28 E. M. Howard

We present a basis for studying questions of cause and effect in statistics which subsumes and reconciles the models proposed by Pearl, Robins, Rubin and others, and which, as far as mathematical notions and notation are concerned, is…

Statistics Theory · Mathematics 2023-04-18 José A. Ferreira

Quantum mechanics allows for coherent control over the order in which different processes take place on a target system, giving rise to a new feature known as indefinite causal order. Indefinite causal order provides a resource for quantum…

The expression of causality depends on an underlying choice of chronology. Since a chronology is provided by any Lorentzian metric in relativistic theories, there are as many expressions of causality as there are non-conformally related…

High Energy Physics - Theory · Physics 2007-05-23 Jean-Philippe Bruneton

We demonstrate in the context of the minisuperspace model consisting of a closed Friedmann-Robertson-Walker universe coupled to a scalar field that Vilenkin's tunneling wavefunction can only be consistently defined for particular choices of…

General Relativity and Quantum Cosmology · Physics 2009-10-31 N. Kontoleon , D. L. Wiltshire

In relational quantum dynamics, evolution emerges via the correlations between some system of interest and a clock system, which plays the role of a temporal reference frame. Their combined state satisfies a Wheeler-de Witt-like constraint…

Quantum Physics · Physics 2026-03-11 Veronika Baumann , Maximilian P. E. Lock

An operational description of quantum phenomena concerns developing models that describe experimentally observed behaviour. $\textit{Higher-order quantum operations}\unicode{x2014}$quantum operations that transform quantum…

Quantum Physics · Physics 2025-03-14 Philip Taranto , Simon Milz , Mio Murao , Marco Túlio Quintino , Kavan Modi

Causality in quantum field theory is defined by the vanishing of field commutators for space-like separations. However, this does not imply a direction for causal effects. Hidden in our conventions for quantization is a connection to the…

High Energy Physics - Theory · Physics 2019-10-30 John F. Donoghue , Gabriel Menezes

All covariant time operators with normalized probability distribution are derived. Symmetry criteria are invoked to arrive at a unique expression for a given Hamiltonian. As an application, a well known result for the arrival time…

Quantum Physics · Physics 2015-05-19 G. C. Hegerfeldt , J. G. Muga

A new interpretation of quantum mechanics, similar to the Copenhagen interpretation, is developed from time-symmetry arguments and commonly held principles concerning time and causality. These principles, which are grounded in ideas outside…

Quantum Physics · Physics 2007-05-23 William R. Wharton

The causality issues concerning Hegerfeldt's paradox and the localization of relativistic quantum systems are addressed through a proper-time formalism of single-particle operators. The proposed description does not depend on classical…

Quantum Physics · Physics 2020-09-29 E. R. F. Taillebois , A. T. Avelar

In section.1 the objectivity in science is presented shortly. In section.2 some details concerning the objectivity in the case of the mechanical movement description of a material particle are given. In section.3 details concerning the…

Classical Physics · Physics 2018-06-13 Agneta M. Balint , Stefan Balint

The causality properties of linear time-varing systems under constant time lags are investigated based on the definition and use of the definitions of appropriate Hankel and Toeplitz causal and anticausal operators.

Dynamical Systems · Mathematics 2009-02-18 M. De la Sen

Causality has been the issue of philosophic debate since Hippocrates. It is used in formal verification and testing, e.g., to explain counterexamples or construct fault trees. Recent work defines actual causation in terms of Pearl's…

Logic in Computer Science · Computer Science 2019-11-01 Robert Künnemann , Deepak Garg , Michael Backes

We present new results on the causality violations introduced by the rotating wave approximation commonly used in quantum optics and high-energy physics. We find that the causality violations and faster-than-light signalling induced by the…

Quantum Physics · Physics 2019-10-02 Nicholas Funai , Eduardo Martin-Martinez

Causality is one of the most fundamental -- and yet elusive -- concepts in physics. From its intuitive role in everyday experience to its formal and often implicit role in scientific theories, causality has challenged philosophers and…

Popular Physics · Physics 2026-01-05 Alessandro De Angelis

In this paper, we analyse the Wheeler-DeWitt equation in the third quantized formalism. We will demonstrate that for certain operator ordering, the early stages of the universe are dominated by quantum fluctuations, and the universe becomes…

General Physics · Physics 2016-03-23 Yoshiaki Ohkuwa , Mir Faizal , Yasuo Ezawa

Causal reasoning is essential to science, yet quantum theory challenges it. Quantum correlations violating Bell inequalities defy satisfactory causal explanations within the framework of classical causal models. What is more, a theory…

Quantum Physics · Physics 2021-03-05 Jonathan Barrett , Robin Lorenz , Ognyan Oreshkov

In a causal world the direction of the time arrow dictates how past causal events in a variable $X$ produce future effects in $Y$. $X$ is said to cause an effect in $Y$, if the predictability (uncertainty) about the future states of $Y$…

Chaotic Dynamics · Physics 2018-07-24 Ezequiel Bianco-Martinez , Murilo S. Baptista

A recent paper [P. Martin-Dussaud, C. Rovelli, F. Zalamea, arXiv:1806.08150] has given a lucid treatment of Bell's notion of local causality within the framework of the relational interpretation of quantum mechanics. However, the authors…

Quantum Physics · Physics 2020-01-08 Jacques Pienaar