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Related papers: Inflation in $R^2$ supergravity with non-minimal s…

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We construct a model of quintessential inflation in Palatini $R^2$ gravity employing a scalar field with a simple exponential potential and coupled to gravity with a running non-minimal coupling. At early times, the field acts as the…

General Relativity and Quantum Cosmology · Physics 2022-11-03 Konstantinos Dimopoulos , Alexandros Karam , Samuel Sánchez López , Eemeli Tomberg

The Starobinsky model was born in a cosmological scenario where conformally coupled matter quantum field fluctuations on the vacuum drive a non trivial semiclassical energy momentum tensor quadratic in curvature. The presence of an unstable…

High Energy Physics - Theory · Physics 2025-02-20 Roberto Percacci , Gian Paolo Vacca

The most current observational data corroborate the Starobinsky model as one of the strongest candidates in the description of an inflationary regime. Motivated by such success, extensions of the Starobinsky model have been increasingly…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 G. Rodrigues-da-Silva , J. Bezerra-Sobrinho , L. G. Medeiros

As is well known, the gravitational degrees of freedom contained in $R+\zeta R^{2}$ (super)gravity lead to Starobinsky's potential, in a one-field setting for inflationary Cosmology that appears favored by Planck data. In this letter we…

General Relativity and Quantum Cosmology · Physics 2017-02-01 Andrea Addazi , Maxim Yu. Khlopov

The Starobinsky inflationary model of $(R+R^2)$ gravity is extended to the new-minimal (40+40) off-shell 4D, N=2 supergravity in N=2 chiral (curved) superspace. In its dual formulation, as a matter-coupled N=2 Einstein supergravity,…

High Energy Physics - Theory · Physics 2014-05-07 Sergei V. Ketov

We show how we can implement chaotic inflation in the context of supergravity by conveniently selecting the functional form of a strong enough non-minimal coupling between the inflaton and the Ricci scalar curvature. The procedure can be…

High Energy Physics - Phenomenology · Physics 2014-12-12 C. Pallis

We present a two-field inflation model where inflaton field has a non-canonical kinetic term due to the presence of a dilaton field. It is a two-parameter generalization of one-parameter Brans-Dicke gravity in the Einstein frame. We show…

High Energy Physics - Phenomenology · Physics 2016-08-03 Girish Kumar Chakravarty , Suratna Das , Gaetano Lambiase , Subhendra Mohanty

We present a supergravity inflationary scenario in which the inflaton field takes values considerably larger than the Planck scale. It is based on a class of inflationary potentials which can be derived from ``singular'' Kaehler potentials…

High Energy Physics - Phenomenology · Physics 2009-10-31 C. Panagiotakopoulos

We elaborate on the predictions of the imaginary Starobinsky model of inflation coupled to matter, where the inflaton is identified with the imaginary part of the inflaton multiplet suggested by the Supergravity embedding of a pure R + R^2…

High Energy Physics - Theory · Physics 2016-01-20 Sergio Ferrara , Alex Kehagias , Antonio Riotto

We propose a class of inflation models in which the coefficient of the inflaton kinetic term rapidly changes with energy scale. This may occur especially if the inflaton moves over a long distance during inflation as in the case of…

High Energy Physics - Phenomenology · Physics 2014-11-21 Fuminobu Takahashi

In this work we investigate a inflationary scenario generated by a large scalar field $\phi$ that non-minimally couples to a $f(R)$ modified gravity model. For a Starobinsky's like model, it is found that along a particular flat direction,…

High Energy Physics - Phenomenology · Physics 2017-01-17 Romy H. S. Budhi

We study several extensions of the Starobinsky model of inflation, which obey all observational constraints on the inflationary parameters, by demanding that both the inflaton scalar potential in the Einstein frame and the $F(R)$ gravity…

General Relativity and Quantum Cosmology · Physics 2022-03-30 Vsevolod R. Ivanov , Sergei V. Ketov , Ekaterina O. Pozdeeva , Sergey Yu. Vernov

We consider a broad class of inflationary models that arise naturally in supergravity. They are defined in terms of a parameter $\alpha$ that determines the curvature and cutoff of these models. As a function of this parameter, we exhibit…

High Energy Physics - Theory · Physics 2015-06-19 Renata Kallosh , Andrei Linde , Diederik Roest

We point out that in the large field regime, the recently proposed superconformal D-term inflation model coincides with the Starobinsky model. In this regime, the inflaton field dominates over the Planck mass in the gravitational kinetic…

High Energy Physics - Theory · Physics 2015-06-16 W. Buchmuller , V. Domcke , K. Kamada

We review inflationary cosmology in modified gravity such as $R^2$ gravity with its extensions in order to generalize the Starobinsky inflation model. In particular, we explore inflation realized by three kinds of effects: modification of…

High Energy Physics - Theory · Physics 2015-03-11 Kazuharu Bamba , Sergei D. Odintsov

We discuss N=1 supergravity inflationary models based on two chiral multiplets, the inflaton and the goldstino superfield. Using superconformal methods for these models, we propose to replace the unconstrained chiral goldstino multiplet by…

High Energy Physics - Theory · Physics 2015-06-22 Sergio Ferrara , Renata Kallosh , Andrei Linde

We consider an inflationary model motivated by quantum effects of gravitational and matter fields near the Planck scale. Our Lagrangian is a re-summed version of the effective Lagrangian recently obtained by Demmel, Saueressig and…

General Relativity and Quantum Cosmology · Physics 2018-08-15 Lei-Hua Liu , Tomislav Prokopec , Alexei A. Starobinsky

We present novel implementations of Starobisky-like inflation within Supergravity adopting Kaehler potentials for the inflaton which parameterize hyperbolic geometries known from the T-model inflation. The associated superpotentials are…

High Energy Physics - Phenomenology · Physics 2025-03-07 C. Pallis

We study a model of inflation with terms quadratic and logarithmic in the Ricci scalar, where the gravitational action is $f(R)=R+\alpha R^2+\beta R^2 \ln R$. These terms are expected to arise from one loop corrections involving matter…

High Energy Physics - Theory · Physics 2015-06-19 Ido Ben-Dayan , Shenglin Jing , Mahdi Torabian , Alexander Westphal , Lucila Zarate

We propose new supergravity models describing chaotic Linde- and Starobinsky-like inflation in terms of a single chiral superfield. The key ideas to obtain a positive vacuum energy during large field inflation are (i) stabilization of the…

High Energy Physics - Theory · Physics 2014-08-15 Sergei V. Ketov , Takahiro Terada