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Related papers: Physical time for the beginning universe

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We consider a simple cosmological model consisting of an empty Bianchi I Universe, whose Hamiltonian we deparametrise to provide a natural clock variable. The model thus effectively describes an isotropic universe with an induced clock…

General Relativity and Quantum Cosmology · Physics 2022-01-26 Przemysław Małkiewicz , Patrick Peter , S. D. P. Vitenti

We investigate Rindler's frame measurements. From its perspective, we found a geometric/gravitational interpretation of speed of light, mass and uncertainty principle. This can be interpreted as measurements of a black hole universal clock.…

General Physics · Physics 2021-07-23 Ahmed Farag Ali

Quantum optics potentially offers an information channel from the Universe beyond the established ones of imaging and spectroscopy. All existing cameras and all spectrometers measure aspects of the first-order spatial and/or temporal…

Astrophysics · Physics 2015-06-24 Dainis Dravins

Collapse models possibly suggest the need for a better understanding of the structure of space-time. We argue that physical space, and space-time, are emergent features of the Universe, which arise as a result of dynamical collapse of the…

Quantum Physics · Physics 2017-02-01 Tejinder P. Singh

The time evolution of the universe is usually mathematically described under a continuous time and thus time reversible. Here, the consequences of studying the evolution of a homogenous isotropic universe by time continuous reversible…

General Physics · Physics 2019-10-23 Roland Riek

There are discernible and fundamental differences between clocks, waves and physical states in classical physics. These fundamental concepts find a common expression in the context of quantum physics in gravitational fields; matter and…

Quantum Physics · Physics 2015-05-28 C. S. Unnikrishnan , George T. Gillies

A stationary line element of general relativity seems to be compatible to essential cosmological facts (though only as far as one can expect solving the nonlinear Einstein equations neglecting local cosmic evolution and all spatial…

General Physics · Physics 2007-05-23 Peter Ostermann

Einstein's theory of general relativity is based on the premise that the physical laws take the same form in all coordinate systems. However, it still presumes a preferred decomposition of the total kinematic Hilbert space into local…

General Relativity and Quantum Cosmology · Physics 2021-04-28 Sung-Sik Lee

It is argued that any operational measure of time is inseparably bound to the presence of a periodic process in some medium. Since, as first formulated by Einstein's (1905) equation for the energy, all "particles" (neutrons, electrons,…

Quantum Physics · Physics 2007-05-23 Gerhard Groessing

The starting point of this work is the principle that all movement of particles and photons must follow geodesics of a 4-dimensional space where time intervals are always a measure on geodesic arc lengths. The last 3 coordinates (alpha =…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Jose B. Almeida

The general world model for homogeneous and isotropic universe has been roposed. For this purpose, we introduce a global and fiducial system of reference (world reference frame) constructed on a 5-dimensional space-time that is embedding…

Astrophysics · Physics 2008-03-04 Chan-Gyung Park

Classical clocks measure proper time along their worldline, and Riemannian geometry provides tools for predicting the time shown by clocks in both flat and curved spacetimes. Common approaches to time in quantum systems, based for instance…

General Relativity and Quantum Cosmology · Physics 2025-01-14 Joseph Balsells , Martin Bojowald

We consider spacetime to be a 4-dimensional differentiable manifold that can be split locally into time and space. No metric, no linear connection are assumed. Matter is described by classical fields/fluids. We distinguish electrically…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Friedrich W. Hehl , Yuri N. Obukhov

It is proposed that spacetime should be regarded as an evolving block universe, bounded to the future by the present time, which continually extends to the future. This future boundary is defined at each time by measuring proper time along…

General Relativity and Quantum Cosmology · Physics 2015-06-22 George F R Ellis

Even though the concepts of time and space are basic concepts of physics, they have not been vouchsafed a constructive definition. As to space, this is no wonder because a correct notion of space cannot be formed in the frame of the…

General Physics · Physics 2007-05-23 Yefim Bakman , Boris Pogorelsky

In this paper we propose that cosmological time is a quantum observable that does not commute with other quantum operators essential for the definition of cosmological states, notably the cosmological constant. This is inspired by…

General Relativity and Quantum Cosmology · Physics 2020-02-11 Joao Magueijo , Lee Smolin

Recent advances in observational cosmology are changing the way we view the nature of time. In general relativity, the freedom in choosing a time hypersurface has hampered the implementation of the theory. Fortunately, Hamilton-Jacobi…

Astrophysics · Physics 2007-05-23 D. S. Salopek

Massive fields in the primordial universe function as standard clocks and imprint clock signals in the density perturbations that directly record the scale factor of the primordial universe as a function of time, a(t). A measurement of such…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-03 Xingang Chen , Abraham Loeb , Zhong-Zhi Xianyu

A new model of the observed universe, using solutions to the full Einstein equations, is developed from the hypothesis that our observable universe is an underdense bubble, with an internally inhomogeneous fractal bubble distribution of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 David L. Wiltshire

The problem of the Nature of Time is twofold: whether or not time is a fundamental quantity of Nature, and how does clock time of metrology emerge in the experimental description of dynamics. This work strongly supports the fundamental…

Classical Physics · Physics 2013-11-05 Enrico Prati