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Related papers: A Universe that does not know the time

200 papers

There are theories which implement the idea that the constants of nature may be "time dependent." These introduce new fields representing "evolving constants," in addition to physical fields. We argue that dynamical matter coupling…

General Relativity and Quantum Cosmology · Physics 2018-07-27 Syed Moeez Hassan , Viqar Husain , Babar Qureshi

In this paper we address the problem of the arrow of time from a cosmological point of view, rejecting the traditional entropic approach that defines the future direction of time as the direction of the entropy increase: from our…

Quantum Physics · Physics 2009-11-07 Mario Castagnino , Luis Lara , Olimpia Lombardi

The nature of time in quantum mechanics is closely related to the use of a complex, rather than say real, Hilbert space. This becomes particularly clear when considering quantum field theory in time dependent backgrounds, such as in…

General Relativity and Quantum Cosmology · Physics 2011-11-03 G. W. Gibbons

Quantum Theory, similar to Relativity Theory, requires a new concept of space-time, imposed by a universal constant. While velocity of light $c$ not being infinite calls for a redefinition of space-time on large and cosmological scales,…

History and Philosophy of Physics · Physics 2021-04-21 Herbert Capellmann

The cosmological constant $\Lambda$ can be achieved as the result of entangled and statistically correlated minisuperspace cosmological states, built up by using a minimal choice of observable quantities, i.e. $\Omega_{m}$ and $\Omega_{k}$,…

General Relativity and Quantum Cosmology · Physics 2015-05-20 S. Capozziello , O. Luongo

The quantum theory of a spatially flat Friedmann-Robertson-Walker universe with a massless scalar field as source is further investigated. The classical model is singular, and in the framework of the Arnowitt-Deser-Misner canonical…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Nivaldo A. Lemos

We continue our analysis of a quantum cosmology model describing a flat Friedmann--Lema\^itre--Robertson--Walker universe filled with a (free) massless scalar field and an arbitrary perfect fluid. For positive energy density in the scalar…

General Relativity and Quantum Cosmology · Physics 2022-04-08 Steffen Gielen , Lucía Menéndez-Pidal

We are at a specific period of modern cosmology, during which the large increase of the amount of data leads to the idea that the determination of cosmological parameters has been achieved with a rather good precision. There is a large…

Astrophysics · Physics 2017-08-23 A. Blanchard

A model quantum cosmology is used to illustrate how arrows of time emerge in a universe governed by a time-neutral dynamical theory constrained by time asymmetric initial and final boundary conditions represented by initial and final…

General Relativity and Quantum Cosmology · Physics 2020-02-18 James B. Hartle

In the last years several theoretical papers discussed if time can be an emergent property deriving from quantum correlations. Here, to provide an insight into how this phenomenon can occur, we present an experiment that illustrates Page…

The application of quantum theory to cosmology raises a number of conceptual questions, such as the role of the quantum-mechanical notion of "observer" or the absence of a time variable in the Wheeler-DeWitt equation. I point out that a…

History and Philosophy of Physics · Physics 2018-04-20 Francesca Vidotto

In this paper we build on our previous work and the work of Peter Lynds within a Bohmian framework to consider the intervallic structure of thermodynamic reversibility as well as presenting new considerations for the measurement of…

General Physics · Physics 2011-05-10 Maurice Passman , Philip V. Fellman , Jonathan Vos Post

The familiar textbook quantum mechanics of laboratory measurements incorporates a quantum mechanical arrow of time --- the direction in time in which state vector reduction operates. This arrow is usually assumed to coincide with the…

Quantum Physics · Physics 2015-06-12 James B. Hartle

This paper gives an elementary introduction to some of the conceptual problems of quantum cosmology. Contents: 1. Why quantum cosmology? 2. Time in quantum gravity 3.Decoherence and the recovery of the Schrodinger equation 4. The direction…

General Relativity and Quantum Cosmology · Physics 2009-09-25 C. Kiefer

Arrows of time - thermodynamical, cosmological, electromagnetic, quantum mechanical, psychological - are basic properties of Nature. For a quantum system-bath closed system the de-correlated initial conditions and no-memory (Markovian)…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 V. G. Gurzadyan , S. Sargsyan , G. Yegorian

The problem of the physical nature and the cosmological genesis of Lambda-term is discussed. This problem can't be solved in terms of the current quantum field theory which operates with Higgs and non-perturbative vacuum condensates and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. Burdyuzha , O. Lalakulich , G. Vereshkov , Yu. Ponomarev

Some principles underpinning the running of the Universe are discussed. The most important, the machine principle, states that the Universe is a fully autonomous, self-organizing and self-testing quantum automaton. Continuous space and…

Quantum Physics · Physics 2009-09-25 George Jaroszkiewicz

In this review, I discuss briefly how the presence of a cosmological constant in the Universe may imply a decoherent evolution of quantum matter in it, and as a consequence a fundamental irreversibility of time unrelated in principle to CP…

General Relativity and Quantum Cosmology · Physics 2007-05-23 N. E. Mavromatos

Quantum timeless approaches solve the problem of time by recovering the usual unitary evolution of quantum theory relative to a clock in a stationary quantum Universe. For some Hamiltonians of the Universe, such as those including an…

Quantum Physics · Physics 2026-04-14 Simone Rijavec

In addressing the cosmological constant problem, we propose that the discrepancy between the theoretical and observed values can be ascribed to the inherent uncertainty in the spacetime metric. Mach's principle, which posits that mass…

General Relativity and Quantum Cosmology · Physics 2023-09-06 Ahmed Farag Ali , Nader Inan