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Related papers: Dissipative Emergence of Inflation from Quasi-Cycl…

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We study an inflation model with a flat scalar potential supported by observations and find that slow-roll inflation can emerge after a quasi-cyclic phase of the Universe, where it undergoes repeated expansions and contractions for a finite…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Hiroki Matsui , Alexandros Papageorgiou , Fuminobu Takahashi , Takahiro Terada

We provide a realisation of a singularity-free inflationary universe in the form of a simple cosmological model dominated at early times by a single minimally coupled scalar field with a physically based potential. The universe starts…

General Relativity and Quantum Cosmology · Physics 2008-11-26 George F. R. Ellis , Jeff Murugan , Christos G. Tsagas

Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful `cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both…

High Energy Physics - Theory · Physics 2009-11-10 Neil Turok , Paul J. Seinhardt

In this paper we present an informal description of the Cyclic Inflation scenario which allows our universe to "start" with a negative potential energy, inflate, and then gracefully exit to a positive potential energy universe. We discuss…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-06 Tirthabir Biswas , Tomi Koivisto , Anupam Mazumdar

Loop quantum cosmology provides a nice solution of avoiding the big bang singularity through a big bounce mechanism in the high energy region. In loop quantum cosmology an inflationary universe is emergent after the big bounce, no matter…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Xin Zhang , Yi Ling

We give a consistent description of how the inflationary Universe emerges in quantum cosmology. This involves two steps: Firstly, it is shown that a sensible probability peak can be obtained from the cosmological wave function. This is…

General Relativity and Quantum Cosmology · Physics 2009-10-31 A. Barvinsky , A. Kamenshchik , C. Kiefer

We investigate the early-time accelerated universe after the Big Bang. We pay attention to the dissipative properties of the inflationary universe in the presence of a soft type singularity, making use of the parameters of the generalized…

General Relativity and Quantum Cosmology · Physics 2017-03-23 I. Brevik , A. V. Timoshkin

An outgrowth of the idea of inflation is advanced. In the inflation regime, the singularity condition is broken. Equations which govern inflation are invariant under time reversal, so that they describe deflation as well. Those two…

General Physics · Physics 2009-11-02 Vladimir S. Mashkevich

We propose a new class of inflationary solutions to the standard cosmological problems (horizon, flatness, monopole,...), based on a modification of old inflation. These models do not require a potential which satisfies the normal…

High Energy Physics - Theory · Physics 2007-05-23 Gia Dvali , Shamit Kachru

We consider the description of cosmological dynamics from the onset of inflation by a perfect fluid whose parameters must be consistent with the strength of the enhanced quantum loop effects that can arise during inflation. The source of…

General Relativity and Quantum Cosmology · Physics 2010-04-14 N. C. Tsamis , R. P. Woodard

Closed, singularity-free, inflationary cosmological models have recently been studied in the context of general relativity. Despite their appeal, these so called emergent models suffer from a number of limitations. These include the fact…

Astrophysics · Physics 2009-11-10 David J. Mulryne , Reza Tavakol , James E. Lidsey , George F. R. Ellis

The early universe according to the big bang and the grand unified theories is discussed. The shortcomings of big bang are summarized together with their resolution by inflationary cosmology. Inflation, the subsequent oscillation and decay…

High Energy Physics - Phenomenology · Physics 2007-05-23 George Lazarides

We discuss various models of inflationary universe with $\Omega \not = 1$. A homogeneous universe with $\Omega > 1$ may appear due to creation of the universe "from nothing" in the theories where the effective potential becomes very steep…

Astrophysics · Physics 2016-08-30 Andrei Linde , Arthur Mezhlumian

We contrast the possibility of inflation starting a) from the universe's inception or b) from an earlier non-inflationary state. Neither case is ideal since a) assumes quantum mechanical reasoning is straightforwardly applicable to the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 D. H. Coule

We review here some recent results that show that inflationary cosmological models must contain initial singularities. We also present a new singularity theorem. The question of the initial singularity re-emerges in inflationary cosmology…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Arvind Borde , Alexander Vilenkin

The aim of this paper is to show, that the 'oscillating universe' is a viable alternative to inflation. We remind that this model provides a natural solution to the flatness or entropy and to the horizon problem of standard cosmology. We…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Ruth Durrer , Joachim Laukenmann

Open Inflation has recently been suggested as a possible way out of the age crisis caused by observations of a large rate of expansion of the universe, in conflict with the existence of very old globular clusters. It proposes that our local…

Astrophysics · Physics 2009-10-28 Juan Garcia-Bellido

In this paper, we investigate the evolution of the early universe within an emergent fractional cosmological framework. The underlying formulation is conceptually rooted in generalized measure constructions, closely related to fractal…

General Relativity and Quantum Cosmology · Physics 2026-04-16 S. M. M. Rasouli

Inflation provides a natural mechanism to account for the origin of cosmic structures. The generation of primordial inhomogeneities during inflation can be understood via the spontaneous creation of quanta from the vacuum. We show that when…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ivan Agullo , Leonard Parker

A model of a universe without big bang singularity is presented, which displaysanearly inflationary period ending just before a phase transition to a deflationary epoch. The model produces enough heavy particles so as to reheat the universe…

General Relativity and Quantum Cosmology · Physics 2016-09-05 Jaume de Haro , Emilio Elizalde
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