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Related papers: A Stochastic Measure for Eternal Inflation

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The slow-roll inflation paradigm can be systematically generalized within the framework of non-standard entropy formalisms, giving rise to a broad class of inflationary models that deviate from the conventional Bekenstein--Hawking case. We…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-26 H R M Zarandi , Esmaiel Ebrahimi , Yo Toda

The possibility that the non-minimal coupling inflation could be eternal is investigated. We calculate the quantum fluctuation of the inflaton in a Hubble time and find that it has the same value as in the minimal case in the slow-roll…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Chao-Jun Feng , Xin-Zhou Li

An extremely fast exponential expansion of the Universe is typical for the stable version of the inflationary model, based on the anomaly-induced action of gravity. The total amount of exponential $e$-folds could be very large, before the…

High Energy Physics - Theory · Physics 2021-08-05 Wagno Cesar e Silva , Ilya L. Shapiro

The probability of there being sufficient inflation to solve the fine-tuning associated with the horizon and flatness problems has recently been shown to be exponentially small, within the context of classical general relativity. Here this…

General Relativity and Quantum Cosmology · Physics 2007-08-27 William Nelson

We examine the inflationary modes in the cubic curvature theories in the context of asymptotically safe gravity. On the phase space of the Hubble parameter, there exists a critical point which corresponds to the slow-roll inflation in…

General Relativity and Quantum Cosmology · Physics 2012-08-09 Sungwook E. Hong , Young Jae Lee , Heeseung Zoe

We here investigate bulk-viscosity driven quasi de-Sitter inflation, that is, the period of accelerated expansion in the early universe during which $-\dot{H}\ll H^2$, with $H(t)$ being the Hubble expansion rate. We do so in the framework…

General Relativity and Quantum Cosmology · Physics 2024-02-21 Sayantani Lahiri , Luciano Rezzolla

We present here a general relativistic mechanism for accelerated cosmic expansion and the Hubble's constant. It is shown that spacetime vorticity coupled to the magnetic field density in galaxies causes the galaxies to recede from one…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-20 Babur M. Mirza

We propose to describe the acceleration of the universe by introducing a model of two coupled fluids. We focus on the accelerated expansion at the early stages. The inflationary expansion is described in terms of a van der Waals equation of…

General Relativity and Quantum Cosmology · Physics 2018-05-28 I. Brevik , V. V. Obukhov , A. V. Timoshkin

The basic motivation of this work is to attempt to explain the rapid primordial inflation and the observed slow late-time inflation by using the Brans-Dicke theory of gravity. We show that the ratio of these two inflation parameters is…

General Relativity and Quantum Cosmology · Physics 2009-11-10 M. Arik , M. C. Calik

The observational constraints on the primordial power spectrum have tightened considerably with the release of the first year analysis of the WMAP observations, especially when combined with the results from other CMB experiments and galaxy…

High Energy Physics - Phenomenology · Physics 2009-11-10 Dominik J. Schwarz , Cesar A. Terrero-Escalante

Eternally inflating universes can contain large thermalized regions with different values of the constants of Nature and with different density fluctuation spectra. To find the probability for a `typical' observer to detect a certain set of…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Alexander Vilenkin

The evolution of the universe from an initial dramatic event, the Big-Bang, is firmly established. Hubble's law [1] (HL) connects the velocity of galactic objects and their relative distance: v(r)=Hr, where H is the Hubble constant. In this…

General Physics · Physics 2015-06-11 Aldo Bonasera

We compute the growth of the mean square of quantum fluctuations of test fields with small effective mass during a slowly changing, nearly de Sitter stage which took place in different inflationary models. We consider a minimally coupled…

High Energy Physics - Theory · Physics 2010-10-11 F. Finelli , G. Marozzi , A. A. Starobinsky , G. P. Vacca , G. Venturi

The theory of eternal inflation in an inflaton potential with multiple vacua predicts that our universe is one of many bubble universes nucleating and growing inside an ever-expanding false vacuum. The collision of our bubble with another…

High Energy Physics - Theory · Physics 2014-06-24 Carroll L. Wainwright , Matthew C. Johnson , Hiranya V. Peiris , Anthony Aguirre , Luis Lehner , Steven L. Liebling

Inflation of a universe filled by an elastic continuous medium is considered. Elastic inflation, while capable of describing current observations, is qualitatively different from standard inflationary models. The scalar and tensor modes…

Astrophysics · Physics 2009-11-10 Andrei Gruzinov

In the standard inflationary paradigm, cosmological density perturbations are generated as quantum fluctuations in the early Universe, but then undergo a quantum-to-classical transition. A key role in this transition is played by squeezing…

General Relativity and Quantum Cosmology · Physics 2020-02-19 Roland de Putter , Olivier Doré

Loop quantum cosmology with a scalar field is known to be closely linked with an inflationary phase. In this article, we study probabilistic predictions for the duration of slow-roll inflation, by assuming a minimalist massive scalar field…

General Relativity and Quantum Cosmology · Physics 2014-07-28 Linda Linsefors , Aurelien Barrau

Models of eternal inflation predict a stochastic self-similar geometry of the universe at very large scales and allow existence of points that never thermalize. I explore the fractal geometry of the resulting spacetime, using…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Serge Winitzki

Some of the parameters we call ``constants of Nature'' may in fact be variables related to the local values of some dynamical fields. During inflation, these variables are randomized by quantum fluctuations. In cases when the variable in…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jaume Garriga , Alexander Vilenkin

We propose a method to extract predictions from quantum cosmology for inflation that can be confronted with observations. Employing the tunneling boundary condition in quantum geometrodynamics, we derive a probability distribution for the…

General Relativity and Quantum Cosmology · Physics 2015-07-21 Gianluca Calcagni , Claus Kiefer , Christian F. Steinwachs
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