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In this paper, we interpret the dark energy as an effect caused by small scale inhomogeneities of the universe with the use of the spatial averaged approach of Buchert. The model considered here adopts the Chevallier-Polarski-Linder(CPL)…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Yan-Hong Yao , Xin-He Meng

In this paper we discuss a cosmological model for a universe with self-regulating features. We set up the theoretical framework for the model and determine the time evolution of the scale-factor $a(t)$. It is shown that such a universe…

General Relativity and Quantum Cosmology · Physics 2024-01-15 Manasse R. Mbonye

The problem of cosmic acceleration and dark energy is one of the mysteries presently posed in the scientific society that general relativity has not been able to solve. In this work, we have considered alternative models to explain this…

General Relativity and Quantum Cosmology · Physics 2022-12-01 M. Koussour , N. Myrzakulov , S. H. Shekh , M. Bennai

We explore how quantum properties of spacetime, specifically the curvature of momentum space, can backreact on classical gravity within a tractable semiclassical (2+1)-dimensional framework with a negative cosmological constant. Motivated…

General Relativity and Quantum Cosmology · Physics 2026-05-13 Partha Nandi , Mainak Roy , Langa Horoto , Frederik G. Scholtz , Biswajit Chakraborty

We investigate the effect of backreaction due to inhomogeneities on the evolution of the present universe within the Buchert framework. Our analysis shows how backreaction from inhomogeneities in the presence of the cosmic event horizon…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-13 Nilok Bose , A. S. Majumdar

I show that a generic quantum phenomenon can drive cosmic acceleration without the need for dark energy or modified gravity. When treating the universe as a quantum system, one typically focuses on the scale factor (of an FRW spacetime) and…

General Relativity and Quantum Cosmology · Physics 2019-09-13 Luke M. Butcher

We discuss the effect of curvature and matter inhomogeneities on the averaged scalar curvature of the present-day Universe. Motivated by studies of averaged inhomogeneous cosmologies, we contemplate on the question whether it is sensible to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Thomas Buchert , Mauro Carfora

General Relativity (GR) is a phenomenologically successful theory that rests on firm foundations, but has not been tested on cosmological scales. The advent of dark energy (and possibly even the requirement of cold dark matter), has…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Constantinos Skordis

The acceleration of the universe can be explained either through dark energy or through the modification of gravity on large scales. In this paper we investigate modified gravity models and compare their observable predictions with dark…

Astrophysics · Physics 2008-11-26 Edmund Bertschinger , Phillip Zukin

We use an alternative interpretation of quantum mechanics, based on the Bohmian trajectory approach, and show that the quantum effects can be included in the classical equation of motion via a conformal transformation on the background…

General Relativity and Quantum Cosmology · Physics 2019-11-20 G. Gregori , B. Reville , B. Larder

Homogeneous and isotropic cosmological models with ordinary matter and gravity predict slower expansion and shorter distances than observed. It is possible that this failure is due the known breakdown of homogeneity and isotropy related to…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-23 Syksy Rasanen

The $f(R)$ gravity models formulated in Einstein conformal frame are equivalent to Einstein gravity together with a minimally coupled scalar field. The scalar field couples with the matter sector and the coupling term is given by the…

General Relativity and Quantum Cosmology · Physics 2012-07-24 Yousef Bisabr

We discuss the recently suggested Ricci-Gauss-Bonnet holographic dark energy in Chern-Simons modified gravity. We have tested some general forms of the scale factor $a(t)$, and used two physically reasonable forms which have been proved to…

General Relativity and Quantum Cosmology · Physics 2020-03-04 Nasr Ahmed

We review some recent developments in the conformal gravity theory that has been advanced as a candidate alternative to standard Einstein gravity. As a quantum theory the conformal theory is both renormalizable and unitary, with unitarity…

High Energy Physics - Theory · Physics 2015-05-27 Philip D. Mannheim

The current understanding of structure formation in the early universe is mainly built on a magnification of quantum fluctuations in an initial vacuum state during an early phase of accelerated universe expansion. One usually describes this…

Astrophysics · Physics 2008-08-06 Martin Bojowald , Aureliano Skirzewski

In a recent Foundations of Physics paper [5] by the current author it was shown that, when the self-force problem of classical electrodynamics is properly solved, it becomes a plausible ontology underlying the statistical description of…

General Physics · Physics 2021-03-09 Yehonatan Knoll

We discuss cosmological effects of the quantum loops of massless particles, which lead to temporal non-localities in the equations of motion governing the scale factor a(t). For the effects discussed here, loops cause the evolution of a(t)…

General Relativity and Quantum Cosmology · Physics 2014-06-11 John F. Donoghue , Basem Kamal El-Menoufi

The acceleration of the expansion of the universe arises from unknown physical processes involving either new fields in high energy physics or modifications of gravitation theory. It is crucial for our understanding to characterize the…

Astrophysics · Physics 2009-11-10 Eric V. Linder

The large-scale homogeneity and isotropy of the universe is generally thought to imply a well defined background cosmological model. It may not. Smoothing over structure adds in an extra contribution, transferring power from small scales up…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-05 Julian Adamek , Chris Clarkson , Ruth Durrer , Martin Kunz

An important open question in cosmology is the degree to which the Friedmann-Lemaitre-Robertson-Walker (FLRW) solutions of Einstein's equations are able to model the large-scale behaviour of the locally inhomogeneous observable universe. We…

General Relativity and Quantum Cosmology · Physics 2013-08-29 Timothy Clifton , Kjell Rosquist , Reza Tavakol
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