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In this paper we will present the \QTR{it}{self-induced approach} to decoherence, which does not require the interaction between the system and the environment: decoherence in closed quantum systems is possible. This fact has relevant…

Quantum Physics · Physics 2011-08-04 Mario Castagnino , Olimpia Lombardi

In this universe, governed fundamentally by quantum mechanical laws, characterized by indeterminism and distributed probabilities, classical deterministic laws are applicable over a wide range of time, place, and scale. We review the origin…

General Relativity and Quantum Cosmology · Physics 2008-02-03 James B. Hartle

The problem investigated in this paper is einselection, i. e. the selection of mutually exclusive quantum states with definite probabilities through decoherence. Its study is based on a theory of decoherence resulting from the projection…

Quantum Physics · Physics 2009-11-10 Roland Omnes

Space-time symmetries and internal quantum symmetries can be placed on equal footing in a hyperspin geometry. Four-dimensional classical space-time emerges as a result of a decoherence that disentangles the quantum and the space-time…

Quantum Physics · Physics 2007-05-23 Dorje C. Brody , Lane P. Hughston

Decoherence may not solve all of the measurement problems of quantum mechanics. It is proposed that a solution to these problems may be to allow that superpositions describe physically real systems in the following sense. Each quantum…

Quantum Physics · Physics 2007-05-23 Paul Merriam

A type of mechanics will be presented that possesses some distinctive properties. On the one hand, its physical description & rules of operation are readily comprehensible & intuitively clear. On the other, it fully satisfies all observable…

Quantum Physics · Physics 2026-02-05 Eric Tesse

We use the decoherent histories approach to quantum theory to compute the probability of a non-relativistic particle crossing $x=0$ during an interval of time. For a system consisting of a single non-relativistic particle, histories…

Quantum Physics · Physics 2009-10-30 J. J. Halliwell , E. Zafiris

The universe we observe is homogeneous on super-horizon scales, leading to the ``cosmic homogeneity problem''. Inflation alleviates this problem but cannot solve it within the realm of conservative extrapolations of classical physics. A…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Mark Trodden , Tanmay Vachaspati

Previous analysis about the deparametrization and path integral quantization of cosmological models are extended to models which do not admit an intrinsic time. The formal expression for the transition amplitude is written down for the Taub…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Gaston Giribet , Claudio Simeone

Decoherent histories quantum theory is reformulated with the assumption that there is one "real" fine-grained history, specified in a preferred complete set of sum-over-histories variables. This real history is described by embedding it in…

Quantum Physics · Physics 2013-09-04 Murray Gell-Mann , James B. Hartle

We argue that, in order to obtain decoherence of spacetime, we should consider quantum conformal metric fluctuations of spacetime. This could be the required environment in the problem of selfmeasurement of spacetime in quantum gravity.

General Relativity and Quantum Cosmology · Physics 2007-05-23 Jose-Luis Rosales , Jose-Luis Sanchez-Gomez

In this letter we review the separate universe approach for cosmological perturbations and point out that it is essentially the lowest order approximation to a gradient expansion. Using this approach, one can study the nonlinear evolution…

Astrophysics · Physics 2009-11-10 G. I. Rigopoulos , E. P. S. Shellard

Friedmann-Lemaitre equations with contributions coming from matter, curvature, cosmological constant, and radiation, when written in terms of conformal time u rather than in terms of cosmic time t, can be solved explicitly in terms of…

General Relativity and Quantum Cosmology · Physics 2018-09-12 Robert Coquereaux

We apply the principles of quantum mechanics and quantum cosmology to predict probabilities for our local observations of a universe undergoing false vacuum eternal inflation. At a sufficiently fine-grained level, histories of the universe…

High Energy Physics - Theory · Physics 2018-01-18 James Hartle , Thomas Hertog

The inherent difficulty in talking about quantum decoherence in the context of quantum cosmology is that decoherence requires subsystems, and cosmology is the study of the whole Universe. Consistent histories gave a possible answer to this…

Quantum Physics · Physics 2021-04-26 Henrique Gomes

Relativity and quantum mechanics are generalized by considering a finite limit for the smallest measurable distance. The value a of this quantum of length is unknown, but it is a universal constant, like c and h. It depends on the total…

General Physics · Physics 2011-08-25 A. Meessen

In this letter we discuss the possibility of treating the spacetime by itself as a kind of deformable body for which we can define an fundamental lattice, just like atoms in crystal lattices. We show three signs pointing in that direction.…

General Relativity and Quantum Cosmology · Physics 2007-05-30 M. O. Tahim , R. R. Landim , C. A. S. Almeida

We present a general analytic method for evaluating the generally time-dependent pointer states of a subsystem, which are defined by their capability not to entangle with the states of another subsystem. In this way, we show how in practice…

Quantum Physics · Physics 2011-04-25 Hoofar Daneshvar , G. W. F. Drake

The most striking observable feature of our indeterministic quantum universe is the wide range of time, place, and scale on which the deterministic laws of classical physics hold to an excellent approximation. This essay describes how this…

Quantum Physics · Physics 2011-05-23 James B. Hartle

We continue our efforts to understand, within the framework of the quantum mechanics of the universe as a whole, the quasiclassical realm of familiar experience as a feature emergent from the Hamiltonian of the elementary particles and the…

Quantum Physics · Physics 2019-05-16 Murray Gell-Mann , James Hartle