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This paper continues the development of a discrete space-time concept that is recently used in the explanation of the cosmological constant. Instead of order estimation, a more theoretical treatment of the theory is introduced. Based on the…

General Physics · Physics 2007-05-23 H. M. Mok

Dynamical system techniques are extremely useful to study cosmology. It turns out that in most of the cases, we deal with finite isolated fixed points corresponding to a given cosmological epoch. However, it is equally important to analyse…

General Relativity and Quantum Cosmology · Physics 2017-03-22 Mariam Bouhmadi-López , João Marto , João Morais , César M. Silva

Geometric discretisation draws analogies between discrete objects and operations on a complex with continuum ones on a manifold. We generalise the theory to the cubic case and incorporate metric, by adding volume factors to our discrete…

High Energy Physics - Theory · Physics 2007-05-23 Samik Sen

The fact that in Minkowski space, space and time are both quantized does not have to be introduced as a new postulate in physics, but can actually be derived by combining certain features of General Relativity and Quantum Mechanics. This is…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. 't Hooft

We examine a simple theoretical model to estimate (by fine tuning condition) the value of the cosmological constant. We assume, in analogy with holographic principle, that cosmological constant, like classical surface tension coefficient in…

Astrophysics · Physics 2008-01-21 V. Pankovic , S. Ciganovic , J. Ivanovic , R. Glavatovic , P. Grujic

We consider cosmological model in 4+1 dimensions with variable scale factor in extra dimension and static external space. The time scale factor is changing. Variations of light velocity, gravity constant, mass and pressure are determined…

General Relativity and Quantum Cosmology · Physics 2007-05-23 W. B. Belayev

We develop a new perspective on the discretization of the phase space structure of gravity in 2+1 dimensions as a piecewise-flat geometry in 2 spatial dimensions. Starting from a subdivision of the continuum geometric and phase space…

General Relativity and Quantum Cosmology · Physics 2020-04-03 Laurent Freidel , Florian Girelli , Barak Shoshany

The holographic principle suggests that the Hilbert space of quantum gravity is locally finite-dimensional. Motivated by this point-of-view, and its application to the observable Universe, we introduce a set of numerical and conceptual…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Oliver Friedrich , Ashmeet Singh , Olivier Doré

Using dynamical systems methods, we describe the evolution of a minimally coupled scalar field and a Friedmann-Lemaitre-Robertson-Walker universe in the context of general relativity, which is relevant for inflation and late-time…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Valerio Faraoni , Charles S. Protheroe

Hilbert space combines the properties of two fundamentally different types of mathematical spaces: vector space and metric space. While the vector-space aspects of Hilbert space, such as formation of linear combinations of state vectors,…

Quantum Physics · Physics 2015-05-27 I. D'Amico , J. P. Coe , V. V. Franca , K. Capelle

Shortly the vacuum component of the Universe from the geometry point of view and from the point of view of the standard model of physics of elementary particles is discussed. Some arguments are given to the calculated value of the…

Astrophysics · Physics 2009-12-15 V. Burdyuzha , G. Vereshkov

In this work, we are investigating the problem of integrability of Bianchi class A cosmological models. This class of systems is reduced to the form of Hamiltonian systems with exponential potential forms. The dynamics of Bianchi class A…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Andrzej J. Maciejewski , Marek Szydlowski

How can one fully harness the power of physics encoded in relativistic $N$-body phase space? Topologically, phase space is isomorphic to the product space of a simplex and a hypersphere and can be equipped with explicit coordinates and a…

High Energy Physics - Phenomenology · Physics 2024-08-26 Tianji Cai , Junyi Cheng , Nathaniel Craig , Giacomo Koszegi , Andrew J. Larkoski

We describe all the localization observables of a quantum particle in a one-dimensional box in terms of sequences of unit vectors in a Hilbert space. An alternative representation in terms of positive semidefinite complex matrices is…

Quantum Physics · Physics 2015-06-26 G. Cassinelli , E. De Vito , P. Lahti , J. -P. Pellonpaa

In this essay, we present a new understanding of the cosmological constant problem, built upon the realization that the vacuum energy density can be expressed in terms of a phase space volume. We introduce a UV-IR regularization which…

High Energy Physics - Theory · Physics 2023-03-31 Laurent Freidel , Jerzy Kowalski-Glikman , Robert G. Leigh , Djordje Minic

We survey results on compact Clifford-Klein forms of homogeneous spaces, with a focus on recent contributions and organized around approaches via topology, geometry and dynamics. In addition, we survey results on moduli spaces of compact…

Differential Geometry · Mathematics 2013-07-09 David Constantine

We consider a (4+d)-dimensional spacetime broken up into a (4-n)-dimensional Minkowski spacetime (where n goes from 1 to 3) and a compact (n+d)-dimensional manifold. At the present time the n compactification radii are of the order of the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 A. G. Agnese , M. La Camera

It has been shown that if one solves self-consistently the semiclassical Einstein equations in the presence of a quantum scalar field, with a cutoff on the number of modes, spacetime become flatter when the cutoff increases. Here we extend…

High Energy Physics - Theory · Physics 2025-04-01 Renata Ferrero , Vincenzo Naso , Roberto Percacci

We consider asymptotic dimension of coarse spaces. We analyse coarse structures induced by metrisable compactifications. We calculate asymptotic dimension of coarse cell complexes. We calculate the asymptotic dimension of certain negatively…

Metric Geometry · Mathematics 2007-05-23 Bernd Grave

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