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Related papers: The Imaginary Starobinsky Model and Higher Curvatu…

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We have presented previously a general treatment of Starobinsky-like inflation in no-scale supergravity where the tensor-to-scalar ratio $r = 3(1 - n_s)^2$, and $n_s$ is the tilt of the scalar perturbations. In particular, we have shown how…

High Energy Physics - Theory · Physics 2019-10-02 John Ellis , Dimitri V. Nanopoulos , Keith A. Olive , Sarunas Verner

The curvaton scenario predicts an almost scale-invariant spectrum of perturbations in most inflation models. We consider the possibility that renormalisable phi^4 or Planck scale-suppressed non-renormalisable curvaton potential terms may…

High Energy Physics - Phenomenology · Physics 2009-11-10 John McDonald

In these lectures, after a short introduction to cosmology, we discuss the supergravity embedding of higher curvature models of inflation. The supergravity description of such models is presented for the two different formulations of…

High Energy Physics - Theory · Physics 2014-10-23 Sergio Ferrara , Alex Kehagias

We present a new approximation scheme that allows us to increase the accuracy of analytical predictions of the power spectra of inflationary perturbations for two specific classes of inflationary models. Among these models are chaotic…

Astrophysics · Physics 2015-06-24 C. A. Terrero-Escalante , D. J. Schwarz , A. A. Garcia

In Cuzinatto et al. [Phys. Rev. D 93, 124034 (2016)], it has been demonstrated that theories of gravity in which the Lagrangian includes terms depending on the scalar curvature $R$ and its derivatives up to order $n$, i.e.…

General Relativity and Quantum Cosmology · Physics 2019-05-07 R. R. Cuzinatto , C. A. M. de Melo , L. G. Medeiros , P. J. Pompeia

Processes of particle production during inflation can increase the amplitude of the scalar metric perturbations. We show that such a mechanism can naturally arise in supergravity models where an axion-like field, whose potential is…

High Energy Physics - Phenomenology · Physics 2021-07-07 Michael A. Roberts , Lorenzo Sorbo

An intermediate inflationary universe model within the context of non-minimally coupled to the scalar curvature is analyzed. We will conduct our analysis under the slow roll approximation of the inflationary dynamics and the cosmological…

General Relativity and Quantum Cosmology · Physics 2017-09-12 Carlos Gonzalez , Ramon Herrera

We argue that the Starobinsky model of inflation, realised via an $R^2$ term in the Lagrangian, can originate from quantum effects due to a tower of light species. By means of two separate arguments, we show how this implies that the scale…

High Energy Physics - Theory · Physics 2024-02-19 Dieter Lust , Joaquin Masias , Benjamin Muntz , Marco Scalisi

In this work, we perform a numerical study of three Starobinsky--type inflationary scenarios: the $\alpha$--Starobinsky inflationary model, the power--law Starobinsky inflationary model, and the power--law $\alpha$--Starobinsky inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-12 Jordan Zambrano , Ángel Rodríguez , Melisa Alvear , Clara Rojas

A modified gravity model of Starobinsky inflation and primordial black hole production was proposed in good (within $1\sigma$) agreement with current measurements of the cosmic microwave background radiation. The model is an extension of…

General Relativity and Quantum Cosmology · Physics 2024-09-06 Sultan Saburov , Sergei V. Ketov

We present a complete numerical treatment of inflationary dynamics under the influence of stochastic corrections from sub-Hubble modes. We discuss how to exactly model the stochastic noise terms arising from the sub-Hubble quantum modes…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-02 Aritra De , Rafid Mahbub

In this paper, we study the Starobinsky model of inflation in the context of gravity's rainbow theory. We propose that gravity rainbow functions can be written in the power-law form of the Hubble parameter. We present a detailed derivation…

General Relativity and Quantum Cosmology · Physics 2016-02-11 Auttakit Chatrabhuti , Vicharit Yingcharoenrat , Phongpichit Channuie

We consider slow-roll inflation in the context of recently proposed four-dimensional effective gravity induced on the world-volume of a three-brane in five-dimensional Einstein gravity. We find significant modifications of the simplest…

High Energy Physics - Phenomenology · Physics 2009-12-30 R Maartens , D Wands , B Bassett , I Heard

Current bounds from the polarization of the CMB predict the scale-invariant gravitational wave (GW) background of inflation to be out of reach for upcoming GW interferometers. This prospect dramatically changes if the inflaton is a…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-10 Valerie Domcke , Mauro Pieroni , Pierre Binétruy

The Starobinsky model is one of the inflation models consistent with the result of CMB observation by the Planck satellite. We consider the dynamics of the Starobinsky inflation in the presence of another scalar field with a large…

High Energy Physics - Phenomenology · Physics 2016-05-25 Shinta Kasuya , Kanto Moritake

The goal of this work on mathematical cosmology and geometric methods in modified gravity theories, MGTs, is to investigate Starobinsky-like inflation scenarios determined by gravitational and scalar field configurations mimicking…

General Physics · Physics 2018-05-29 R. Aschheim , L. Bubuianu , Fang Fang , Klee Irwin , V. Ruchin , S. Vacaru

We show that a new class of helical phase inflation models can be simply realized in minimal supergravity, wherein the inflaton is the phase component of a complex field and its potential admits a deformed helicoid structure. We find a new…

High Energy Physics - Theory · Physics 2015-10-19 Tianjun Li , Zhijin Li , Dimitri V. Nanopoulos

We point out that inflationary superhorizon fluctuations can be effectively described by a set of equations analogous to those governing a superfluid. This is achieved through a functional Schr\"odinger approach to the evolution of the…

General Relativity and Quantum Cosmology · Physics 2025-06-05 Gianmassimo Tasinato

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

It is shown that Starobinsky-like potentials can be realized in non-geometric flux compactifications of string theory, where the inflaton involves an axion whose shift symmetry can protect UV-corrections to the scalar potential. For that…

High Energy Physics - Theory · Physics 2015-05-06 Ralph Blumenhagen , Anamaria Font , Michael Fuchs , Daniela Herschmann , Erik Plauschinn