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Related papers: Comments on Space-Time

200 papers

In a recent paper [arXiv:1206.4916] by T. Padmanabhan, it was argued that our universe provides an ideal setup to stress the issue that cosmic space is emergent as cosmic time progresses and that the expansion of the universe is due to the…

General Relativity and Quantum Cosmology · Physics 2012-11-09 Rong-Gen Cai

Maxwell's equations cannot describe a homogeneous and isotropic universe with a uniformly distributed net charge, because the electromagnetic field tensor in such a universe must be vanishing everywhere. For a closed universe with a nonzero…

General Relativity and Quantum Cosmology · Physics 2016-03-01 Li-Xin Li

Understanding the expansion of the Universe remains a profound challenge in fundamental physics. The complexity of solving General Relativity equations in the presence of intricate, inhomogeneous flows has compelled cosmological models to…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-18 P. Tremblin , G. Chabrier

Quantum mechanical unitarity in our universe is challenged both by the notion of the big bang, in which nothing transforms into something, and the expansion of space, in which something transforms into more something. This motivates the…

High Energy Physics - Theory · Physics 2022-02-08 Jordan Cotler , Andrew Strominger

The nature of space-time and surrounding matter objects was and persists to be a one of the most intriguing and challenging problems facing the mankind and natural scientists especially. As we know one of the most brilliant inventions in…

General Relativity and Quantum Cosmology · Physics 2008-10-26 Anatoliy K. Prykarpatsky , Nikolai N. Bogolubov

This paper presents an information-theoretic view of how an observer within a quantum system will perceive his world. It is argued that because of the indistinguishability of quantum particles, a coherent state will appear to an observer…

Astrophysics · Physics 2007-05-23 Subhash Kak

It is very likely that the quantum description of spacetime is quite different from what we perceive at large scales, $l\gg (G\hbar/c^3)^{1/2}$. The long wave length description of spacetime, based on Einstein's equations, is similar to the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 T. Padmanabhan

Developments in theoretical cosmology in the recent decades show a close connection with particle physics, quantum gravity and unified theories. Answers or hints to many fundamental questions in cosmology like the homogeneity and isotropy…

General Relativity and Quantum Cosmology · Physics 2007-05-23 B. L. Hu

Non-empty space reading of Maxwell equations as local energy identities explains why a Coulomb field is carried rigidly by electrons in experiments. The analytical solution of the Poisson equation defines the sharp radial shape of charged…

General Physics · Physics 2015-11-03 I. E. Bulyzhenkov

This review consists of two parts. The first part establishes certain astrophysical bounds on the smoothness of classical spacetime. Some of the best bounds to date are based on the absence of vacuum Cherenkov radiation in ultrahigh-energy…

High Energy Physics - Phenomenology · Physics 2008-11-26 F. R. Klinkhamer

Since Hawking's 1974 discovery, we expect that a black hole formed by collapse will emit radiation and eventually disappear. Closely related to the information loss puzzle is the challenge to define an objective notion of physical entropy…

High Energy Physics - Theory · Physics 2023-03-31 Bernard S. Kay

Understanding the evolution of entropy in the universe is a fundamental aspect of cosmology. This paper investigates the evolution of entropy in a spatially flat $K=0$ universe, focusing on the contributions of matter, radiation, and dark…

General Relativity and Quantum Cosmology · Physics 2025-07-16 Tanisha Joshi , S. D Pathak

We investigate the sensitivity of a universe's nuclear entropy after Big Bang nucleosynthesis (BBN) to variations in both the baryon-to-photon ratio and the temporal evolution of cosmological expansion. Specifically, we construct…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-22 Charlie F. Sharpe , Luke A. Barnes , Geraint F. Lewis

The theoretical foundations of quantum mechanics and de Broglie-Bohm mechanics are analyzed and it is shown that both theories employ a formal approach to microphysics. By using a realistic approach it can be established that the internal…

Quantum Physics · Physics 2007-05-23 W. A. Hofer

A spherical Lagrangian hydrodynamical code has been written to study the formation of cosmological structures in the early Universe. In this code we take into account the presence of collisionless non-baryonic cold dark matter (CDM), the…

Astrophysics · Physics 2009-11-06 O. D. Miranda , J. C. N. de Araujo

A structured collection of thought provoking conclusions about space and time is given. Using only the Compton wavelength lambda = hbar / m c and the Schwarzschild radius r_s = 2 G m / c^2, it is argued that neither the continuity of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Christoph Schiller

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 Cartesian material space approach to Maxwell's equations reveals the analytical solution of the continuous radial density for the extended elementary charge. Radial charges and their Coulomb fields carry equal passive and active…

General Physics · Physics 2017-09-12 I. E. Bulyzhenkov

We present a simple gedanken experiment in which a compact object traverses a spacetime with three macroscopic spatial dimensions and $n$ compact dimensions. The compactification radius is allowed to vary, as a function of the object's…

General Relativity and Quantum Cosmology · Physics 2023-05-08 Matthew J. Lake , Shi-Dong Liang , Anucha Watcharapasorn

Examination of the Einstein energy-momentum relationship suggests that simple unbound forms of matter exist in a four-dimensional Euclidean space. Position, momentum, velocity, and other vector quantities can be expressed as Euclidean…

Quantum Physics · Physics 2007-05-23 Paul J. Freitas