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Related papers: Causal horizon from quantum fluctuations

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We show how the quantum potential arises in various ways and trace its connection to quantum fluctuations and Fisher information along with its realization in terms of Weyl curvature. It is a quantization factor for certain classical…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Robert Carroll

We begin with a brief summary of issues encountered involving causality in quantum theory, placing careful emphasis on the assumptions involved in results such as the EPR paradox and Bell's inequality. We critique some solutions to the…

Quantum Physics · Physics 2017-05-23 Blake K Winter

The fundamental dynamics of quantum particles is neutral with respect to the arrow of time. And yet, our experiments are not: we observe quantum systems evolving from the past to the future, but not the other way round. A fundamental…

Quantum Physics · Physics 2022-11-01 Giulio Chiribella , Zixuan Liu

The time evolution of a closed system of mean fields and fluctuations is Hamiltonian, with the canonical variables parameterizing the general time-dependent Gaussian density matrix of the system. Yet, the evolution manifests both quantum…

High Energy Physics - Phenomenology · Physics 2009-10-28 Salman Habib , Yuval Kluger , Emil Mottola , Juan Pablo Paz

Spacetime undergoes quantum fluctuations, giving rise to spacetime foam, a.k.a. quantum foam. We discuss some properties of spacetime foam, and point out the conceptual interconnections in the physics of quantum foam, black holes, and…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Y. Jack Ng

We argue that theories of quantum gravity constructed with the help of (Causal) Dynamical Triangulations have given us the most informative, quantitative models to date of quantum spacetime. Most importantly, these are derived dynamically…

High Energy Physics - Theory · Physics 2015-06-15 J. Ambjorn , S. Jordan , J. Jurkiewicz , R. Loll

By extending the quantum evolution of a scalar field in time-dependent backgrounds to the complex-time plane and transporting the in-vacuum along a closed path, we argue that the geometric transition from the simple pole at infinity…

High Energy Physics - Theory · Physics 2015-06-16 Sang Pyo Kim

We investigate the question, "how does time flow?" and show that time may change by inversions as well. We discuss its implications to a simple class of linear systems. Instead of introducing any unphysical behaviour, inversions can lead to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Dhurjati Prasad Datta

We provide a (simplified) quantum description of primordial black holes at the time of their formation. Specifically, we employ the horizon quantum mechanics to compute the probability of black hole formation starting from a simple quantum…

General Relativity and Quantum Cosmology · Physics 2019-09-04 R. Casadio , A. Giugno , A. Giusti , M. Lenzi

We consider the evolution of quantum fields on a classical background space-time, formulated in the language of differential geometry. Time evolution along the worldlines of observers is described by parallel transport operators in an…

High Energy Physics - Theory · Physics 2007-05-23 Dirk Graudenz

We here conjecture that two much-studied aspects of quantum gravity, dimensional flow and spacetime fuzziness, might be deeply connected. We illustrate the mechanism, providing first evidence in support of our conjecture, by working within…

High Energy Physics - Theory · Physics 2017-11-15 Giovanni Amelino-Camelia , Gianluca Calcagni , Michele Ronco

Causal asymmetry is one of the great surprises in predictive modelling: the memory required to predict the future differs from the memory required to retrodict the past. There is a privileged temporal direction for modelling a stochastic…

It is the purpose of the present article to collect arguments for, that there should exist in fact -- although not necessarily yet found -- some law, which imply an adjustment to special features to occur in the future. In our own "complex…

General Physics · Physics 2015-03-31 Holger Bech Nielsen

The time-dependent variational principle using generalized Gaussian trial functions yields a finite dimensional approximation to the full quantum dynamics and is used in many disciplines. It is shown how these 'semi-quantum' dynamics may be…

chao-dyn · Physics 2009-10-22 Arjendu K. Pattanayak , William C. Schieve

The consistent histories approach to quantum mechanics is traditionally based on linearly ordered sequences of events. We extend the histories formalism to sets of events whose causal ordering is described by directed acyclic graphs. The…

General Relativity and Quantum Cosmology · Physics 2007-05-23 R. F. Blute , I. T. Ivanov , P. Panangaden

We revisit the quantum theory of a massive, minimally coupled scalar field, propagating on the Planck-era isotropic cosmological quantum spacetime which transitions to a classical spacetime in later times. The quantum effects modify the…

General Relativity and Quantum Cosmology · Physics 2020-03-06 Saeed Rastgoo , Yaser Tavakoli , Julio C. Fabris

In the macroscopic world, time is intrinsically asymmetric, flowing in a specific direction, from past to future. However, the same is not necessarily true for quantum systems, as some quantum processes produce valid quantum evolutions…

We provide a mechanism by which, from a background independent model with no quantum mechanics, quantum theory arises in the same limit in which spatial properties appear. Starting with an arbitrary abstract graph as the microscopic model…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Fotini Markopoulou , Lee Smolin

In the process of work it has been found that space-time quantum fluctuations are naturally described in terms of the deformation parameter introduced on going from the well-known quantum mechanics to that at Planck scales and put forward…

General Physics · Physics 2013-06-13 A. E. Shalyt-Margolin

The causal interpretation of quantum mechanics is applied to the universe as a whole and the problem of cluster formation is studied in this framework. It is shown that the quantum effects be the source of the cluster formation.

Astrophysics · Physics 2007-05-23 Ali Shojai , Fatimah Shojai