English
Related papers

Related papers: Reconstructing square-law k-inflation from Planck …

200 papers

In this paper, we propose a new method to calculate the mode functions in the noncommutative power-law inflation model. In this model, all the modes created when the stringy space-time uncertainty relation is satisfied are generated inside…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-02 Chao-Jun Feng , Xin-Zhou Li , Dao-Jun Liu

Using Hamilton-Jacobi formalism, The scenario of warm inflation with viscous pressure is considered. The formalism gives a way of computing the slow-rolling parameters without extra approximation, and it is well-known as a powerful method…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-17 L. Akhtari , A. Mohammadi , K. Sayar , Kh. Saaidi

In the framework of gravitational models obtained from the Geometric Inflation's proposal, where an infinite tower of curvature scalars are included into the action, we compute the slow-roll parameters by the Hubble slow-roll approach. We…

General Relativity and Quantum Cosmology · Physics 2020-09-02 Gustavo Arciniega , Luisa Jaime , Gabriella Piccinelli

The inflationary cosmology paradigm is very successful in explaining the CMB anisotropy to the percent level. Besides the dependence on the inflationary model, the power spectra, spectral tilt and non-Gaussianity of the CMB temperature…

High Energy Physics - Theory · Physics 2014-02-18 Amjad Ashoorioon , Konstantinos Dimopoulos , M. M. Sheikh-Jabbari , Gary Shiu

The dependence of cosmological and inflationary parameters on time during the last 60 e-folds in inflation is investigated using a slow-roll inflation model. The time dependence of the inflaton field is calculated for the case of chaotic…

Astrophysics · Physics 2008-12-15 Shiro Hirai , Tomoyuki Takami

Inflationary models within string theory exhibit unusual scalar field dynamics involving non-minimal kinetic terms and generically referred to as k-inflation. In this situation, the standard slow-roll approach used to determine the behavior…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-08 Christophe Ringeval

In this paper, we compare brane inflation models with the Planck data and the pre-Planck data (which combines WMAP, ACT, SPT, BAO and H0 data). The Planck data prefer a spectral index less than unity at more than 5\sigma confidence level,…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-09 Yin-Zhe Ma , Qing-Guo Huang , Xin Zhang

The constraints on a general form of the power-law potential and the dissipation coefficient in the framework of warm single field inflation imposed by Planck data will be investigated. {By Considering a quasi-static Universe, besides a…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Zahra Ghadiri , Abdollah Refaei , Ali Aghamohammadi , Haidar Sheikhahmadi

We investigate an ability of the exponential power-law inflation to be phenomenologically correct model of the early universe. GR scalar cosmology equations we study in Ivanov-Salopek-Bond (or Hamilton-Jacobi like) representation where the…

General Relativity and Quantum Cosmology · Physics 2025-01-22 I. V. Fomin , S. V. Chervon

We propose a chaotic inflation model in supergravity based on polynomial interactions of the inflaton. Specifically we study the chaotic inflation model with quadratic, cubic and quartic couplings in the scalar potential and show that the…

High Energy Physics - Phenomenology · Physics 2015-06-15 Kazunori Nakayama , Fuminobu Takahashi , Tsutomu T. Yanagida

We propose a single field inflationary model by generalizing the inverse power law potential from the intermediate model. We study the implication of our model on the primordial anisotropy of cosmological microwave background radiation.…

High Energy Physics - Theory · Physics 2015-06-17 Zhun Lu

We present results obtained by a software we developed for computing observational cosmological inflation parameters: the scalar spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) for a standard single field and tachyon inflation,…

General Relativity and Quantum Cosmology · Physics 2019-03-27 Milan Milošević , Neven Bilić , Dragoljub D. Dimitrijević , Goran S. Djordjevic , Marko Stojanović

We implement a procedure by which the parameters present in the potential of Quartic Hilltop Inflation (QHI) are eliminated in favor of the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$. By doing this it is posible to…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 Gabriel German

The Starobinsky model predicts a primordial inflation period without the presence of an inflaton field. The modified version of this model predicts a simple time dependence for the Hubble parameter $H(t)$, which decreases slowly between the…

Astrophysics · Physics 2015-06-24 Reuven Opher , Ana Pelinson

A correction to the Quartic Hilltop inflationary model is proposed to account for stabilising terms in the potential. We derive analytical predictions for the spectral index $n_s$ and tensor-scalar ratio $r$ which lie within the Planck 2018…

General Relativity and Quantum Cosmology · Physics 2022-01-05 Josh Hoffmann , David Sloan

In scale-invariant models of fundamental physics all mass scales are generated via spontaneous symmetry breaking. In this work, we study inflation in scale-invariant quadratic gravity, in which the Planck mass is generated classically by a…

General Relativity and Quantum Cosmology · Physics 2023-05-05 Anish Ghoshal , Debangshu Mukherjee , Massimiliano Rinaldi

Rubano and Barrow have discussed the emergence of a dark energy, with late-time cosmic acceleration arising from a self-interacting homogeneous scalar field with a potential of hyperbolic power type. Here, we study the evolution of this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Spyros Basilakos , John D. Barrow

Recent ACT data favor a higher scalar spectral index $n_s$, placing models such as $\alpha$-attractor T-models and natural Inflation in tension with current observations. We propose a K-inflation framework with a field-dependent…

General Relativity and Quantum Cosmology · Physics 2026-05-05 Milad Solbi , Daris Samart , Peera Simakachorn

We analyze the consequences of different evolutions of the Hubble parameter on the spectrum of scalar inflationary perturbations. The analysis is restricted to inflationary phases described by a transient evolution, when uncommon features…

General Relativity and Quantum Cosmology · Physics 2023-04-12 Leonardo Chataignier , Alexander Yu. Kamenshchik , Alessandro Tronconi , Giovanni Venturi

We revisit spectator field models including curvaton and modulated reheating scenarios, specifically focusing on their viability in the new Planck era, based on the derived expression for the spectral index in general spectator field…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-23 Takeshi Kobayashi , Fuminobu Takahashi , Tomo Takahashi , Masahide Yamaguchi