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Padmanabhan [arXiv:1206.4916] argues that the cosmic acceleration can be understood from the perspective that spacetime dynamics is an emergence phenomena. By calculating the difference between the surface degrees of freedom and the bulk…

General Relativity and Quantum Cosmology · Physics 2013-04-19 Ahmad Sheykhi

The evolution of a universe with Brans-Dicke gravity and nonzero curvature is investigated here. We present the equations of motion and their solutions during the radiation dominated era. In a Friedman-Robertson-Walker cosmology we show…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Janna Levin , Katherine Freese

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

In this paper, we show that Padmanabhan's conjecture for the emergence of cosmic space [arXiv:1206.4916] holds for the flat Friedmann-Robertson-Walker universe in Einstein gravity but does not hold for the non-flat case unless one uses the…

High Energy Physics - Theory · Physics 2014-05-05 Ee Chang-Young , Daeho Lee

We study the modified Friedmann equation in the Friedmann-Robertson-Walker universe with quantum effect. Our modified results mainly stem from the new entropy-area relation and the novel idea of T. Padmanabhan, who considers the cosmic…

General Relativity and Quantum Cosmology · Physics 2018-03-15 Wei Zhang , Xiao-Mei Kuang

An emergence of cosmic space has been suggested by Padmanabhan in [arXiv:1206.4916]. This new interesting approach argues that the expansion of the universe is due to the difference between the number of degrees of freedom on a holographic…

High Energy Physics - Theory · Physics 2014-04-17 Ahmed Farag Ali

Considering space--time to be non-commutative, we study the evolution of the universe employing the approach of Newtonian cosmology. Generalizing the conservation of energy and the first law of thermodynamics to $\kappa$-deformed…

General Relativity and Quantum Cosmology · Physics 2023-07-31 E. Harikumar , Harsha Sreekumar , Suman Kumar Panja

Recently, it was argued that the spacetime dynamics can be understood by calculating the difference between the degrees of freedom on the boundary and in the bulk in a region of space. In this Letter, we apply this new idea to braneworld…

High Energy Physics - Theory · Physics 2015-06-16 A. Sheykhi , M. H. Dehghani , S. E. Hosseini

In this paper we describe the evolution of the Universe in terms of the Friedmann equation, which takes into account of the composition and geometry of the Universe. The dependence of the solution on the geometry and composition for…

Popular Physics · Physics 2020-11-02 Vinicius S. Aderaldo , Victor P. Goncalves

The Einstein equations of general relativity reduce, when the spacetime metric is of the Friedmann--Lemaitre--Robertson--Walker type governing an isotropic and homogeneous universe, to the Friedmann equations, which is a set of nonlinear…

General Relativity and Quantum Cosmology · Physics 2024-07-30 Yisong Yang

The classical and quantum models of the Friedmann universe originally filled with a scalar field and radiation have been studied. The radiation has been used to specify a reference frame that makes it possible to remove ambiguities in…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. V. Kuzmichev

In this paper, we propose a model in which an additional pressure due to the effects of the entropic force is added to the ideal fluid. Furthermore, we obtain the dynamic equation in the FRW universe which contains the quantum gravitational…

High Energy Physics - Theory · Physics 2016-03-08 Fei-Quan Tu , Yi-Xin Chen

The classical Friedmann-Lema\^itre equations are solved using a corrected version of Planck's radiation law. The function curves of the scale parameter a(t) and the variations with temperature a(T) and t(T) are given. It is shown that a…

General Relativity and Quantum Cosmology · Physics 2014-10-08 Rainer Collier

In this paper we present the equations of the evolution of the universe in $D$ spatial dimensions, as a generalization of the work of Lima \citep{lima}. We discuss the Friedmann-Robertson-Walker cosmological equations in $D$ spatial…

General Relativity and Quantum Cosmology · Physics 2012-07-09 R. F. L. Holanda , S. H. Pereira

It is shown that density fluctuations obey a scaling law in an open Friedmann universe. In a flat universe, the fluctuations are not scale-invariant. We compute the growth rate of adiabatic scale-invariant density fluctuations in flat, open…

Astrophysics · Physics 2007-05-23 Elcio Abdalla , Roya Mohayaee

The investigation of quantum gravity effects in order to avoid the big bang singularity is a requisite, so that the idea of oscillating universes is introduced as an alternative for standard cosmological model. Therefore, the Friedmann…

General Relativity and Quantum Cosmology · Physics 2018-04-18 Amin. Salehi , Mojtaba. Mahmoudi fard

As is well known, the exact evolution equation of the curvature perturbation plays a very important role in investigation of the inflation power spectrum of the flat universe. However, its corresponding exact extension for the non-flat…

Astrophysics · Physics 2008-11-26 De-Hai Zhang , Cheng-Yi Sun

The IKKT matrix model yields an emergent space-time. We further develop these ideas and give a proposal for an emergent metric. Based on previous numerical studies of this model, we provide evidence that the emergent space-time is…

High Energy Physics - Theory · Physics 2022-09-21 Suddhasattwa Brahma , Robert Brandenberger , Samuel Laliberte

The discovery that the expansion of the universe is accelerating in time is a major discovery which still awaits adequate explanation. It is generally agreed that this implies a cosmic repulsion as a result of the existence of a…

General Physics · Physics 2008-11-26 R. F. O'Connell

In `entropic cosmology', instead of a cosmological constant $\Lambda$, an extra driving term is added to the Friedmann equation and the acceleration equation, taking into account the entropy and the temperature on the horizon of the…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-14 Nobuyoshi Komatsu , Shigeo Kimura
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