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Related papers: How Many $e$-Folds Should We Expect from High-Scal…

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We show that, for a given fixed value of the number of e-folds of the homogeneous solution, inflation succeeds with order unity inhomogeneities in the initial conditions above a characteristic value of the tensor-to-scalar ratio $r$. In…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-16 Panagiotis Giannadakis , Matthew Elley , Raphael Flauger , Eugene A. Lim

It has become standard practice to take the logarithmic growth of the scale factor as a measure of the amount of inflation, despite the well-known fact that this is only an approximation for the true amount of inflation required to solve…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-02 Sirichai Chongchitnan

It is very difficult to obtain a realistic model of a closed inflationary universe. Even if one fine-tunes the total number of e-folds to be sufficiently small, the resulting universe typically has large density perturbations on the scale…

Astrophysics · Physics 2009-09-29 Andrei Linde

The model of fresh inflation with increasing cosmological parameter provides sufficient e-folds to solve the flatness/horizon problem and the density fluctuations agree with experimental values. In this model the temperature increases…

High Energy Physics - Phenomenology · Physics 2009-11-10 Mauricio Bellini

In [arXiv:1102.1513] we introduced an inflationary scenario, Non-Abelian Gauge Field Inflation or gauge-flation for short, in which slow-roll inflation is driven by non-Abelian gauge field minimally coupled to gravity. We present a more…

High Energy Physics - Phenomenology · Physics 2015-03-18 A. Maleknejad , M. M. Sheikh-Jabbari

Stochastic effects in multi-field inflationary scenarios are investigated. A hierarchy of diffusion equations is derived, the solutions of which yield moments of the numbers of inflationary $e$-folds. Solving the resulting partial…

High Energy Physics - Theory · Physics 2016-08-24 Hooshyar Assadullahi , Hassan Firouzjahi , Mahdiyar Noorbala , Vincent Vennin , David Wands

For zero spatial curvature, cosmological phase space of Starobinsky and extended Starobinsky inflationary model show three apparent attractors; the fixed angle attractor in the large field limit, the final attractor representing reheating…

General Relativity and Quantum Cosmology · Physics 2025-06-27 Theppawan Rukpakawong , Piyabut Burikham

We discuss a new scenario for early cosmology, when inflationary de Sitter phase dynamically emergent. This genuine quantum effect occurs as a result of dynamics of the topologically nontrivial sectors in a (conjectured) strongly coupled…

High Energy Physics - Phenomenology · Physics 2014-08-13 Ariel R. Zhitnitsky

We demonstrate that a broad class of modular inflation models predicts the emergence of new physics within an energy range of approximately \( 10^{15} \, \mathrm{GeV} \) to \( 10^{17} \, \mathrm{GeV} \). This prediction arises by comparing…

High Energy Physics - Theory · Physics 2025-08-11 Shuntaro Aoki , Hajime Otsuka

Assuming that the e-folding number is just determined by the change of the scale factor, the tachyonic inflation theory in LQC has been discussed. Considering the tachyon field with exponential potential and inverse quadratic potential, we…

General Relativity and Quantum Cosmology · Physics 2014-12-16 Kui Xiao , Xiao-Kai He , Fei Huang , Jian-Yang Zhu

We consider the well motivated model of the (standard) supersymmetric F-term hybrid inflation (FHI) which can be realized close to the grand unification scale. The predicted scalar spectral index $n_s$ cannot be smaller than 0.98 and can…

High Energy Physics - Phenomenology · Physics 2015-05-13 C. Pallis

We argue that all the necessary ingredients for successful inflation are present in the flat directions of the Minimally Supersymmetric Standard Model. We show that out of many gauge invariant combinations of squarks, sleptons and Higgses,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Rouzbeh Allahverdi , Juan Garcia-Bellido , Kari Enqvist , Anupam Mazumdar

Inflationary models of the early universe provide a natural mechanism for the formation of large scale structure. This success brings to forefront the question of naturalness: Does a sufficiently long slow roll inflation occur generically…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Abhay Ashtekar , David Sloan

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 study a simple extension of Linde's hybrid inflation model, with the inflaton mass term replaced by the most general renormalizable potential for $\phi$. The unprocessed power spectrum of density perturbations can have two minima and one…

Astrophysics · Physics 2009-10-22 Yun Wang

The quantum gravitational scale of inflation is calculated by finding a sharp probability peak in the distribution function of chaotic inflationary cosmologies driven by a scalar field with large negative constant $\xi$ of nonminimal…

General Relativity and Quantum Cosmology · Physics 2009-10-22 A. O. Barvinsky , A. Yu. Kamenshchik

We consider a model of inflation which has recently been proposed in the literature and where inflation is induced by corrections to the energy density coming from the non-commutativity of spacetime. We show that the very rapid inflationary…

General Relativity and Quantum Cosmology · Physics 2013-01-14 Hideki Perrier , Ruth Durrer , Massimiliano Rinaldi

In this paper, we investigate the no-boundary wave function and the complex-valued instantons for two-field inflation models that have different masses. If there is a relatively massive direction, to classicalize the massive field, the…

General Relativity and Quantum Cosmology · Physics 2015-05-08 Dong-il Hwang , Soo A Kim , Dong-han Yeom

By studying the chameleon model during inflation, we investigate whether it can be a successful inflationary model, wherein we employ the common typical potential usually used in the literature. Thus, in the context of the slow-roll…

General Relativity and Quantum Cosmology · Physics 2018-04-13 Nasim Saba , Mehrdad Farhoudi

Large classes of standard single-field slow-roll inflationary models consistent with the required number of e-folds, the current bounds on the spectral index of scalar perturbations, the tensor-to-scalar ratio, and the scale of inflation…

High Energy Physics - Theory · Physics 2023-04-04 Steven Abel , Andrei Constantin , Thomas R. Harvey , Andre Lukas