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Necessary and sufficient conditions allowing a previously unknown space to be explored through scanning operators are reexamined with respect to measure theory. Generalized conceptions of distances and dimensionality evaluation are…

General Physics · Physics 2007-05-23 Michel Bounias , Volodymyr Krasnoholovets

In this paper it is studied the cosmology of a homogeneous and isotropic spacetime endorsed with a conformally coupled massless scalar field. We find six different solutions of the Friedmann equation that represent six different types of…

General Relativity and Quantum Cosmology · Physics 2017-09-20 Salvador J. Robles-Perez

In this paper we treat the black hole horizon as a physical boundary to the spacetime and study its dynamics following from the Gibbons-Hawking-York boundary term. Using the Kerr black hole as an example we derive an effective action that…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Jianwei Mei

The gravitational path-integral of Gauss-Bonnet gravity is investigated and the transition from one spacelike boundary configuration to another is analyzed. Of particular interest is the case of Neumann and Robin boundary conditions which…

General Relativity and Quantum Cosmology · Physics 2025-02-04 Manishankar Ailiga , Shubhashis Mallik , Gaurav Narain

Although big bang cosmology effectively models even the most puzzling observational data, it offers no insight into why the cosmological expansion should occur at all. In this paper it is suggested that a finite Universe poses particular…

General Physics · Physics 2007-05-23 Alasdair Macleod

We study the geometry of Euclidean instantons in loop quantum cosmology (LQC) such as those relevant for the no-boundary proposal. Confining ourselves to the simplest case of a cosmological constant in minisuperspace cosmologies, we analyze…

High Energy Physics - Theory · Physics 2018-10-25 Suddhasattwa Brahma , Dong-han Yeom

We consider the possibility of a past and future eternal universe, constructing geodesically complete inflating, loitering, and bouncing spacetimes. We identify the constraints energy conditions in General Relativity place on the building…

High Energy Physics - Theory · Physics 2025-08-25 Damien A. Easson , Joseph E. Lesnefsky

The great emptiness is a possible beginning of the Universe in the infinite past of physical time. For the epoch of great emptiness particles are extremely rare and effectively massless. Only expectation values of fields and average…

General Relativity and Quantum Cosmology · Physics 2021-05-12 C. Wetterich

In a room with five cosmologists there there may easily be ten theories of cosmogenesis. Cosmogenesis is a popular topic for speculation because it is philosophically deep and because such speculations are unlikely to be proven wrong in the…

General Relativity and Quantum Cosmology · Physics 2011-07-27 Ronald J. Adler

Using the extension of the standard Hawking-Hartle prescription for defining a wave function for the universe, we show that it is possible, given a suitable form for the scalar field potential, to have the universe begin at its largest size…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Daniel Green , W. G. Unruh

We extend the the concept of Hawking-Moss, or up-tunnelling, transitions in the early universe to include black hole seeds. The black hole greatly enhances the decay amplitude, however, order to have physically consistent results, we need…

High Energy Physics - Theory · Physics 2020-10-28 Ruth Gregory , Ian G Moss , Naritaka Oshita , Sam Patrick

If our observable Universe is only a tiny region of a vastly larger and conformally older spacetime, then the usual formulations of the classical flatness and horizon problems of the Hot Big Bang can be reinterpreted as artifacts…

General Relativity and Quantum Cosmology · Physics 2026-02-12 Meir Shimon

An interesting idea is that the universe could be spontaneously created from nothing, but no rigorous proof has been given. In this paper, we present such a proof based on the analytic solutions of the Wheeler-DeWitt equation (WDWE).…

General Relativity and Quantum Cosmology · Physics 2014-04-07 Dongshan He , Dongfeng Gao , Qing-yu Cai

If we assume that the initial conditions for the universe were such that there was no volume-extensive entropy `at the beginning of time' (which is true in Linde's chaotic inflation), we can formulate a covariant holographic bound on the…

High Energy Physics - Theory · Physics 2007-05-23 Michal Fabinger

This article is an introductory work to a larger research project devoted to pure, applied and philosophical aspects of dimension theory. It concerns a novel approach toward an alternate dimension theory foundation: the point-dimension…

History and Philosophy of Physics · Physics 2022-06-14 Nadir Maaroufi , El Hassan Zerouali

The Euclidean path integral approach to quantum gravity is conventionally formulated in terms of the Einstein-Hilbert-York-Gibbons-Hawking action, which requires suitable subtractions to produce the correct black hole partition function.…

General Relativity and Quantum Cosmology · Physics 2026-01-06 Jose Beltrán Jiménez , Tomi S. Koivisto

In the present work we discuss a third alternative to explain the latest observational data concerning the accelerating Universe and its different stages. The particle creation mechanism in the framework of non-equilibrium thermodynamics is…

General Relativity and Quantum Cosmology · Physics 2016-05-17 Subenoy Chakraborty , Supriya Pan , Subhajit Saha

A macroscopic universe may emerge naturally from a Planck cell fluctuation by unfolding through a stage of exponential expansion towards a homogeneous cosmological background. Such primordial inflation requires a large and presumably…

High Energy Physics - Theory · Physics 2007-05-23 F. Englert

The evidence for a Big Bang origin of the Universe is truly compelling, though its cause remains a complete mystery. As the cosmic spacetime is revealed to us with ever improving detail, however, we are beginning to refine the range of its…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-01 Fulvio Melia

A new cosmological object in analogy with the concept of a wormhole in general relativity is introduced. As wormholes connect two distant points through a tunnel in spacetime, this new object connects two spacetime through a large mouth…

General Relativity and Quantum Cosmology · Physics 2022-11-28 S. Danial Forghani , S. Habib Mazharimousavi
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