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The emergence of a highly improbable coincidence in cosmological observations speaks to a remarkably simple cosmic expansion. Compelling evidence now suggests that the Universe's gravitational horizon, coincident with the better known…

General Physics · Physics 2019-05-21 Fulvio Melia

We assume that the Universe has a non trivial topology whose compact spatial sections have a volume significantly smaller than the horizon volume. By a topological lens effect, such a "folded" space configuration generates multiple images…

General Relativity and Quantum Cosmology · Physics 2011-05-23 R. Lehoucq , M. Lachieze-Rey , J. P. Luminet

When taking the real, inhomogeneous and anisotropic matter distribution in the semi-local universe into account, there may be no need to postulate an accelerating expansion of the universe despite recent type Ia supernova data. Local…

General Physics · Physics 2010-09-06 Johan Hansson , Jesper Lindkvist

Topology in momentum space is the main characteristics of the ground states of a system at zero temperature, the quantum vacua. The gaplessness of fermions in bulk, on the surface or inside the vortex core is protected by topology.…

High Energy Physics - Phenomenology · Physics 2013-08-30 G. E. Volovik

A set of algebraic equations for the topological properties of space-time is derived, and used to extend general relativity into the Planck domain. A unique basis set of three-dimensional prime manifolds is constructed which consists of…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Marco Spaans

Starting with a field theoretic approach in Minkowski space, the gravitational energy momentum tensor is derived from the Einstein equations in a straightforward manner. This allows to present them as {\it acceleration tensor} = const.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Theo M. Nieuwenhuizen

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

The role of topology in elementary quantum physics is discussed in detail. It is argued that attributes of classical spatial topology emerge from properties of state vectors with suitably smooth time evolution. Equivalently, they emerge…

General Relativity and Quantum Cosmology · Physics 2009-10-28 A. P. Balachandran , G. Bimonte , G. Marmo , A. Simoni

It has been suggested that the acceleration of the Universe may be due to the backreaction of perturbations to the Friedmann-Robertson-Walker background. For a Universe dominated by cold dark matter, it is known that the backreaction of…

Astrophysics · Physics 2008-11-26 Naresh Kumar , Eanna E. Flanagan

We construct a FLRW universe considering an anisotropic scaling between space and time at extremely high and low energies only. In this context, Friedmann equations contain an additional term arising from spatial curvature which implements…

General Relativity and Quantum Cosmology · Physics 2018-12-26 Rodrigo Maier , Ivano Damião Soares

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

General relativity promotes space-time to a physical, dynamical object subject to equations of motion. Quantum gravity, accordingly, must provide a quantum framework for space-time, applicable on the smallest distance scales. Just like…

General Relativity and Quantum Cosmology · Physics 2010-02-15 Martin Bojowald

We explicitly calculate the Green functions describing quantum changes of topology in Friedman-Lemaitre-Robertson-Walker Universes whose spacelike sections are compact but endowed with distinct topologies. The calculations are performed…

General Relativity and Quantum Cosmology · Physics 2010-02-03 Jerome Martin , Nelson Pinto-Neto , Ivano Damiao Soares

Is the universe finite or infinite, and what shape does it have? These fundamental questions, of which relatively little is known, are typically studied within the context of the standard model of cosmology where the universe is assumed to…

General Relativity and Quantum Cosmology · Physics 2022-06-02 Gregory J. Galloway , Marcus A. Khuri , Eric Woolgar

The global topology of the Universe could, in principle, affect quantum systems through boundary condition constraints. We investigate this connection by analyzing how compact, flat, cosmologically inspired topologies, specifically the…

Quantum Physics · Physics 2025-05-14 Evangelos Achilleas Paraskevas , Leandros Perivolaropoulos

Recent surveys seem to support bulk peculiar velocities well in excess of those anticipated by the standard cosmological model. In view of these results, we consider here some of the theoretical implications of large-scale drift motions. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Christos G Tsagas

It is shown that in the weak field approximation the new geometrical approach can lead to the linear field equations for the several independent fields. For the stronger fields and in the second order approximation the field equations…

Mathematical Physics · Physics 2007-09-18 G. I. Garas'ko

We demonstrate that the rapidity and robustness of slow contraction in homogenizing and flattening the universe found in simulations in which the initial conditions were restricted to non-perturbative variations described by a single…

General Relativity and Quantum Cosmology · Physics 2021-07-13 Anna Ijjas , Frans Pretorius , Paul J. Steinhardt , Andrew P. Sullivan

Considering as usual that the underlying geometry of our universe is well described by the spatially flat Friedmann-Lemaitre-Robertson-Walker line element, we review how the background of holonomy corrected Loop Quantum Cosmology (LQC)…

General Relativity and Quantum Cosmology · Physics 2019-05-01 Jaume de Haro , Llibert Aresté Saló , Supriya Pan

In homogeneous and isotropic Friedmann-Robertson-Walker cosmology, the topology of the universe determines its ultimate fate. If the Weak Energy Condition is satisfied, open and flat universes must expand forever, while closed cosmologies…

High Energy Physics - Theory · Physics 2016-12-13 Matthew Kleban , Leonardo Senatore