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Related papers: Localized Steps toward ACT-Favored Inflation

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Recent measurements from the Atacama Cosmology Telescope (ACT), combined with Planck and DESI data, suggest a scalar spectral index $n_s$ higher than the Planck 2018 baseline, thereby placing conventional attractor-type inflationary models…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 Jureeporn Yuennan , Peeravit Koad , Farruh Atamurotov , Phongpichit Channuie

The Atacama Cosmology Telescope (ACT) collaboration has reported a scalar spectral index $ n_s~=~0.9743~\pm~0.0034 $. This is substantially larger than the classical prediction of non-minimally coupled inflation models such as Higgs…

High Energy Physics - Phenomenology · Physics 2025-11-25 J. McDonald

Inflationary models based on a single scalar field $\phi$ with a quadratic potential $V = \frac{1}{2} m^2 \phi^2$ are disfavoured by the recent Planck constraints on the scalar index, $n_s$, and the tensor-to-scalar ratio for cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 John Ellis , Malcolm Fairbairn , Maria Sueiro

We conjecture that the inflation models with trans-Planckian excursions in the field space should be in the swampland. We check this conjecture in a few examples and investigate the constraints on the spectral index for the slow-roll…

High Energy Physics - Theory · Physics 2008-11-26 Qing-Guo Huang

Warm inflation is, as of today, one of the best motivated mechanisms for explaining an early inflationary period. In this paper, we derive and analyze the current bounds on warm inflation with a monomial potential $U\propto \phi^p$, using…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Luca Visinelli

We study models of inflation where the inflaton corresponds to a flat direction in field space and its mass term is generated by gravity mediated soft supersymmetry breaking at high scale. Assuming the inflaton to have non negligible…

High Energy Physics - Phenomenology · Physics 2007-05-23 Laura Covi

With future galaxy surveys, a huge number of Fourier modes of the distribution of the large scale structures in the Universe will become available. These modes are complementary to those of the CMB and can be used to set constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 Zhiqi Huang , Licia Verde , Filippo Vernizzi

Power-law inflation with $a(t) \propto t^m$ is conceptually simple and predicts a scalar tilt $n_s = 1 - 2/m$ compatible with CMB data, but in four-dimensional Einstein gravity it typically yields a tensor-to-scalar ratio $r = 16/m$ that is…

General Relativity and Quantum Cosmology · Physics 2026-02-19 Daniel Oliveira , Seyed Rasouli , Joao Marto , Paulo Moniz

In this paper we investigate power spectrum of a smoothed scalar field. The smoothing leads to the regularisation of the UV divergences and can be related with the internal structure of the considered field or the space itself. We apply…

High Energy Physics - Theory · Physics 2015-05-14 Jakub Mielczarek , Michal Kamionka

We investigate a class of slow roll inflationary models in the light of the recent Cosmic Microwave Background constraints from Planck 2018, ACT DR6, DESI DR1, and BICEP/\textit{Keck} 2018. The combined dataset favors a higher value of the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 Suvashis Maity

We revisit the idea that the inflaton may have dissipated part of its energy into a thermal bath during inflation, considering monomial inflationary potentials and three different forms of dissipation rate. Using a numerical Fokker-Planck…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-06 Guillermo Ballesteros , Alejandro Pérez Rodríguez , Mathias Pierre

We review the attractor properties of the simplest chaotic model of inflation, in which a minimally coupled scalar field is endowed with a quadratic scalar potential. The equations of motion in a flat Friedmann-Robertson-Walker universe are…

Astrophysics · Physics 2009-06-23 L. Arturo Urena-Lopez , Mayra J. Reyes-Ibarra

We study the inflationary period driven by a fermionic field which is non-minimally coupled to gravity in the context of the constant-roll approach. We consider the model for a specific form of coupling and perform the corresponding…

General Relativity and Quantum Cosmology · Physics 2021-07-08 M. Shokri , J. Sadeghi , M. R. Setare

We develop an integral form for the bispectrum in general single-field inflation whose domain of validity includes models of inflation where the background evolution is not constrained to be slowly varying everywhere. Our integral form…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 Peter Adshead , Wayne Hu , V Miranda

In this paper we use two methods to constrain the the canonical single-field slow-roll inflation model. The first method exploits the analytic slow-roll-parameter dependence of primordial perturbations, and the second consists of a…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-17 Jun Li , Guang-Hai Guo

Following the recent Atacama Cosmology Telescope (ACT) results, we consider hilltop inflation where the inflaton is coupled to a curvaton, simultaneously addressing two main challenges faced by conventional hilltop inflation models: the…

High Energy Physics - Phenomenology · Physics 2026-05-12 Wen-Yuan Ai , Stephen F. King , Xin Wang , Ye-Ling Zhou

We derive an $\alpha=1/3$ - attractor potential of slow-roll inflation in the geometric set-up of three intersecting $D7$ branes under $T^6/Z_N$ type of $CY_3$-compactification within type IIB/F theory with some near-conifold regions. The…

High Energy Physics - Theory · Physics 2024-05-01 Arunoday Sarkar , Buddhadeb Ghosh

We study models of modular inflation of the form expected to arise from low energy effective actions of superstring theories. We argue on general grounds that the most likely models of modular slow-roll inflation are small field models in…

High Energy Physics - Theory · Physics 2009-12-15 Ido Ben-Dayan , Ram Brustein , Senarath P. de Alwis

We place observational constraints on slow-variation single-field inflationary models by carrying out the cosmological Monte Carlo simulation with the recent data of Planck combined with the WMAP large-angle polarization, baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-12 Shinji Tsujikawa , Junko Ohashi , Sachiko Kuroyanagi , Antonio De Felice

We show that the coexistence of a non-minimal coupling to gravity $f_{\mathcal{R}}=1+c{\mathcal{R}} \phi^{n/2}$ with a kinetic mixing of the form $f_K = f_{\mathcal{R}}^m$ -- where $n=2$ and 4 and $0.5 \le m \le 10$ -- reconciles chaotic…

High Energy Physics - Phenomenology · Physics 2025-08-15 C. Pallis
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