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Related papers: New Ekpyrotic Quantum Cosmology

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In quantum cosmology, it is expected that the Big Bang singularity is resolved and the universe undergoes a bounce. We find that for Gaussian initial states, matter-gravity entanglement entropy rises rapidly during the bounce, declines, and…

General Relativity and Quantum Cosmology · Physics 2024-09-09 Viqar Husain , Irfan Javed , Sanjeev S. Seahra , Nomaan X

Using non-linear equation of state for pressure and density energy, we show that the universe is began with a smooth and isotropic bounce. We use a non-linear equation of state which is a binary mixture of perfect fluid and dark energy. We…

General Physics · Physics 2010-10-13 Kh. Saaidi , S. Ziaee

The emergent universe scenario is a proposal for resolving the Big Bang singularity problem in the standard Friedmann-Lemaitre-Robertson-Walker cosmology. In the context of this scenario, the Universe originates from a nonsingular static…

General Relativity and Quantum Cosmology · Physics 2021-07-14 Elham Ghorani , Yaghoub Heydarzade

We track the evolution of entropy and black holes in a cyclic universe that undergoes repeated intervals of expansion followed by slow contraction and a smooth (non-singular) bounce. In this kind of cyclic scenario, there is no big crunch…

General Relativity and Quantum Cosmology · Physics 2022-05-09 Anna Ijjas , Paul J. Steinhardt

According to the inflationary scenario of cosmology, all structure in the Universe can be traced back to primordial fluctuations during an accelerated (inflationary) phase of the very early Universe. A conceptual problem arises due to the…

Astrophysics · Physics 2010-04-28 Claus Kiefer , David Polarski

We discuss cosmological models for an eternal universe. Physical observables show no singularity from the infinite past to the infinite future. While the universe is evolving, there is no beginning and no end - the universe exists forever.…

General Relativity and Quantum Cosmology · Physics 2014-08-27 C. Wetterich

We explore the possibility of emergent cosmology using the effective potential formalism. We discover new models of emergent cosmology which satisfy the constraints posed by the cosmic microwave background (CMB). We demonstrate that, within…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Satadru Bag , Varun Sahni , Yuri Shtanov , Sanil Unnikrishnan

A class of $k$-Essence cosmological models, with a power law kinetic term, is quantised in the mini-superspace. It is shown that for a specific configuration, corresponding to a pressureless fluid, a Schr\"odinger-type equation is obtained…

General Relativity and Quantum Cosmology · Physics 2016-12-28 C. R. Almeida , J. C. Fabris , F. Sbisá , Y. Tavakoli

Universe structure emerges in the unreduced, complex-dynamic interaction process with the simplest initial configuration (two attracting homogeneous fields, quant-ph/9902015). The unreduced interaction analysis gives intrinsically creative…

General Physics · Physics 2007-05-23 Andrei P. Kirilyuk

We consider the claim that decoherence explains the emergence of classicality in quantum systems, and conclude that it does not. We show that, given a randomly chosen universe composed of a variety of subsystems, some of which are…

Quantum Physics · Physics 2008-10-27 Steven Weinstein

We consider quantum field theory on a spacetime representing the Big Crunch/Big Bang transition postulated in the ekpyrotic or cyclic cosmologies. We show via several independent methods that an essentially unique matching rule holds…

High Energy Physics - Theory · Physics 2009-11-07 Andrew J. Tolley , Neil Turok

We investigate the appearance of the classical anisotropic universe from the no-boundary quantum state according to the prescription proposed by Hartle, Hawking and Hertog. Our model is homogeneous, anisotropic, closed universes with a…

General Relativity and Quantum Cosmology · Physics 2009-09-02 Kazuya Fujio , Toshifumi Futamase

The big bounce singularity of a simple 5D cosmological model is studied. Contrary to the standard big bang space-time singularity, this big bounce singularity is found to be an event horizon at which the scale factor and the mass density of…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Lixin Xu , Hongya Liu , Beili Wang

We clarify the way in which cosmological perturbations of quantum origin, produced during inflation, assume classical properties. Two features play an important role in this process: First, the dynamics of fluctuations which are presently…

General Relativity and Quantum Cosmology · Physics 2016-10-26 C. Kiefer , D. Polarski

We study the emergence of anisotropic (Bianchi IX) inflationary universes with no-boundary conditions in the path integral approach to quantum gravity. In contrast to previous work, we find no evidence for any limit to how large the…

High Energy Physics - Theory · Physics 2017-04-19 Sebastian F. Bramberger , Shane Farnsworth , Jean-Luc Lehners

Emergence of the classical world from the quantum substrate of our Universe is a long-standing conundrum. I describe three insights into the transition from quantum to classical that are based on the recognition of the role of the…

Quantum Physics · Physics 2018-07-11 Wojciech Hubert Zurek

This paper contains a discussion on the quantum cosmic models, starting with the interpretation that all of the accelerating effects in the current universe are originated from the existence of a nonzero entropy of entanglement. In such a…

General Relativity and Quantum Cosmology · Physics 2010-01-22 Pedro F. Gonzalez-Diaz , Alberto Rozas-Fernandez

As is known, in modified cosmological theories of gravity many of the cosmologies which could not be generated by standard Einstein gravity, can be consistently described by $F(R)$ theories. Using known reconstruction techniques, we…

General Relativity and Quantum Cosmology · Physics 2015-09-16 V. K. Oikonomou

We find a class of solutions for a homogeneous and isotropic universe in which the initially expanding universe stops expanding, experiences contraction, and then expands again (the "bounce"), in the framework of Einstein gravity with a…

General Relativity and Quantum Cosmology · Physics 2019-06-26 Hiroki Matsui , Fuminobu Takahashi , Takahiro Terada

In light of the recent observational data coming from the sky we have two significant directions in the field of theoretical cosmology recently. First, we are now able to make use of present observations, such as the Planck and BICEP2 data,…

High Energy Physics - Theory · Physics 2014-06-19 Yi-Fu Cai
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