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Related papers: Eff-ACT-ive Starobinsky pre-inflation

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We investigate the impact of curvature corrections to Starobinsky inflation in light of the latest observational results from the Atacama Cosmology Telescope (ACT). While the pure Starobinsky model remains a compelling candidate for cosmic…

General Relativity and Quantum Cosmology · Physics 2025-09-18 Andrea Addazi , Yermek Aldabergenov , Sergei V. Ketov

We analyze the Starobinsky inflation model and the impact of curvature corrections, particularly a cubic $R^3$ term, to assess their behavior in light of the latest observational results from the Atacama Cosmology Telescope (ACT). With the…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-30 J. Bezerra-Sobrinho , L. G. Medeiros

We propose a novel non-singular cosmological scenario within the framework of Horndeski gravity, consisting of three successive stages: (i) a Genesis phase, in which the Universe slowly expands from an asymptotically flat spacetime; (ii) a…

General Relativity and Quantum Cosmology · Physics 2025-09-08 Han Gil Choi , Pavel Petrov , Seong Chan Park

The ACT data shows an enhancement in the value of the scalar spectral index, as $n_s = 0.9743 \pm 0.0034$, leading to disfavoring many inflationary models, including the Starobinsky model. To satisfy the constraint made by ACT, we will…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-09 Yogesh , Abolhassan Mohammadi , Qiang Wu , Tao Zhu

We investigate the pre-inflationary dynamics of inflation with the Starobinsky potential, favored by recent data from the Planck mission, using techniques developed to study cosmological perturbations on quantum spacetimes in the framework…

General Relativity and Quantum Cosmology · Physics 2016-03-23 Béatrice Bonga , Brajesh Gupt

Starobinsky inflation and nonminimally coupled (NMC) Higgs inflation have been among the most favored models of the early Universe, as their predictions for the scalar spectral index $n_s$ and tensor-to-scalar ratio $r$ fall comfortably…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Ioannis D. Gialamas , Alexandros Karam , Antonio Racioppi , Martti Raidal

A self-consistent pre-inflationary extension of the inflationary scenario with the Starobinsky potential, favored by Planck data, is studied using techniques from loop quantum cosmology (LQC). The results are compared with the quadratic…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Béatrice Bonga , Brajesh Gupt

We investigate the inflationary phenomenology of a marginally deformed Starobinsky model, motivated by quantum corrections to the $R^{2}$ term, in light of the latest cosmological observations. In this framework, the inflationary potential…

General Relativity and Quantum Cosmology · Physics 2025-09-30 Jureeporn Yuennan , Farruh Atamurotov , Phongpichit Channuie

The $F(R)$ gravity models of inflation are revisited in light of the recent observations of cosmic microwave background radiation by Atacama Cosmology Telescope (ACT) and DESI Collaboration. A detailed study of the evolution equations in…

General Relativity and Quantum Cosmology · Physics 2025-12-18 Sergei V. Ketov , Ekaterina O. Pozdeeva , Sergey Yu. Vernov

We revisit the Starobinsky model of inflation in light of recent data from the Atacama Cosmology Telescope (ACT), which indicates a potential preference for a slightly larger scalar spectral index $n_s$ than predicted by the standard $R^2$…

General Relativity and Quantum Cosmology · Physics 2025-12-25 Andrea Addazi , Yermek Aldabergenov , Daulet Berkimbayev , Yifu Cai

The inflationary and pre-inflationary evolution of scalar modes of cosmological perturbations in a closed universe is analyzed for a loop quantum cosmology model with an inflationary regime consistent with the constraints on inflation…

General Relativity and Quantum Cosmology · Physics 2024-11-26 Lucas M. V. Montese , Nelson Yokomizo

We analyze various phases of inflation based on the anomaly-induced effective action of gravity (modified Starobinsky model), taking the cosmological constant Lambda and k=0, +/- 1 topologies into account. The total number of the…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. M. Pelinson , I. L. Shapiro , F. I. Takakura

We often find in the literature solutions to the Friedmann and fluid equations for simple cosmological models during the matter, radiation or cosmological constant dominated epochs. However no solutions appear for the inflationary era…

General Relativity and Quantum Cosmology · Physics 2020-07-30 Gabriel German

We consider the ghost-free higher order corrections to the Starobinsky model in the old minimal supergravity. In general, higher order corrections cannot be forbidden by symmetries, which likely violate the flatness of the scalaron…

High Energy Physics - Theory · Physics 2015-01-26 Kohei Kamada , Jun'ichi Yokoyama

We examine the power-law Starobinsky model, a generalized version of the Starobinsky inflation model, characterized by a power-law correction to Einstein gravity. Employing the $f(R)$ formalism, the scalar and tensor power spectra were…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-10 Saisandri Saini , Akhilesh Nautiyal

In light of the recent results from the Atacama Cosmology Telescope (ACT), which have provided a notable shift in the constraints on $(n_s, r)$ and placed several otherwise viable models of inflation in tension with the latest data, we…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-03 William J. Wolf

The anomaly-induced inflation (modified Starobinsky model) is based on the application of the effective quantum field theory approach to the Early Universe. We present a brief general review of the model and show that it does not require a…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. M. Pelinson , I. L. Shapiro , J. Sola , F. I. Takakura

Working in the Large Volume Scenario (LVS) of IIB Calabi-Yau flux compactifications, we construct inflationary models from recently computed higher derivative $(\alpha')^3$-corrections. Inflation is driven by a Kaehler modulus whose…

High Energy Physics - Theory · Physics 2016-01-08 Benedict J. Broy , David Ciupke , Francisco G. Pedro , Alexander Westphal

We present cosmological constraints from Planck 2015 data for a universe that is kinetically dominated at very early times. We perform a Markov chain Monte Carlo analysis to estimate parameters and use nested sampling to determine the…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-10 L. T. Hergt , W. J. Handley , M. P. Hobson , A. N. Lasenby

Nonminimal coupling between the inflaton and the Ricci scalar plays a crucial role in shaping the predictions of single-field inflationary models. While a quartic potential with such coupling represents one of the simplest realizations…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-24 Waqas Ahmed , Mansoor Ur Rehman
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