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If cosmological inflation is due to a slowly rolling single inflation field taking trans-Planckian values as suggested by the BICEP2 measurement of primordial tensor modes in CMB, embedding inflation into the Standard Model challenges…

High Energy Physics - Phenomenology · Physics 2014-10-14 Kristjan Kannike , Antonio Racioppi , Martti Raidal

We modify the conformal inflation set-up of \cite{Kallosh:2013hoa}, with a local Weyl invariance, a dynamical Planck scale and an $SO(1,1)$ invariance at high energies, in order to be able to identify the physical scalar with the physical…

High Energy Physics - Theory · Physics 2015-06-19 Renato Costa , Horatiu Nastase

We propose a new mechanism for inflationary model building in the framework of metric-affine gravity. Such a mechanism involves an inflaton non-minimally coupled with the Holst invariant. If the non-minimal coupling function has a zero…

General Relativity and Quantum Cosmology · Physics 2026-04-21 Antonio Racioppi

In scalaron-Higgs inflation the Standard Model Higgs boson is non-minimally coupled to gravity and the Einstein-Hilbert action is supplemented by the quadratic scalar curvature invariant. For the quartic Higgs self-coupling $\lambda$ fixed…

High Energy Physics - Theory · Physics 2019-12-12 Anirudh Gundhi , Christian F. Steinwachs

We study quintessential inflation in the framework of metric-affine gravity. It is well known that non-minimal couplings with the Holst invariant can generate a quasi-pole inflationary behaviour resulting in a Starobinsky-like…

General Relativity and Quantum Cosmology · Physics 2026-03-18 Konstantinos Dimopoulos , Christian Dioguardi , Ioannis D. Gialamas , Antonio Racioppi

Starobinsky inflation is an attractive, fundamental model to explain the Planck measurements, and its higher-order extension may allow us to probe quantum gravity effects. We show that future CMB data combined with the 21cm intensity map…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-30 Tanmoy Modak , Lennart Röver , Björn Malte Schäfer , Benedikt Schosser , Tilman Plehn

We give a brief review of the basic principles of inflationary theory and discuss the present status of the simplest inflationary models that can describe Planck/BICEP/Keck observational data by choice of a single model parameter. In…

High Energy Physics - Theory · Physics 2025-10-28 Renata Kallosh , Andrei Linde

Large-field inflation is an interesting and predictive scenario. Its non-trivial embedding in supergravity was intensively studied in the recent literature, whereas its interplay with supersymmetry breaking has been less thoroughly…

High Energy Physics - Theory · Physics 2015-06-22 Wilfried Buchmuller , Emilian Dudas , Lucien Heurtier , Clemens Wieck

We generalise Starobinsky's model of inflation to space-times with $D>4$ dimensions, where $D-4$ dimensions are compactified on a suitable manifold. The $D$-dimensional action features Einstein-Hilbert gravity, a higher-order curvature…

High Energy Physics - Theory · Physics 2017-02-28 Santiago Pajón Otero , Francisco G. Pedro , Clemens Wieck

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 consider a general chaotic inflation model with non-canonical kinetic term, resulting in attractor solutions for the inflation of quadratic or other monomial type. In particular, the form of the kinetic term and the potential is fixed…

High Energy Physics - Phenomenology · Physics 2015-06-19 Hyun Min Lee

We show that a supersymmetric renormalizable theory based on gauge group SO(10) and Higgs system {\bf {10 $\oplus$ 210 $\oplus$ 126 $\oplus$ $\overline{\bf 126}$}} with no scale supergravity can lead to a Starobinsky kind of potential for…

High Energy Physics - Phenomenology · Physics 2015-10-28 Ila Garg , Subhendra Mohanty

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

In Starobinsky inflation with a Weyl squared Lagrangian $-\alpha C^2$, where $\alpha$ is a coupling constant, we study the linear stability of cosmological perturbations on a spatially flat Friedmann-Lema\^{i}tre-Robertson-Walker…

General Relativity and Quantum Cosmology · Physics 2023-12-15 Antonio De Felice , Ryodai Kawaguchi , Kotaro Mizui , Shinji Tsujikawa

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

The recent measurements of cosmological parameters by the Planck collaboration favors inflationary models with a redshifted spectrum and a very low tensor-to-scalar ratio. Two well-studied scenarios in the particle physics/string theory…

High Energy Physics - Phenomenology · Physics 2014-01-31 Sean Downes

The measurement of a large tensor-to-scalar ratio by the BICEP2 experiment, r = 0.20 (-0.05)(+0.07), severely restricts the landscape of viable inflationary models and shifts attention once more towards models featuring large inflaton field…

High Energy Physics - Phenomenology · Physics 2015-06-19 Keisuke Harigaya , Masahiro Ibe , Kai Schmitz , Tsutomu T. Yanagida

We describe how non-minimal coupling term between the Higgs boson and gravity can lead to the chaotic inflation in the Standard Model without introduction of any additional degrees of freedom. Produced cosmological perturbations are…

High Energy Physics - Phenomenology · Physics 2008-05-16 F. L. Bezrukov

We go a step further in the search for a consistent and realistic supergravity model of large-field inflation by building a class of models with the following features: during slow-roll, all the scalar fields other than the inflaton are…

High Energy Physics - Theory · Physics 2015-06-23 Gianguido Dall'Agata , Fabio Zwirner

We present a general polynomial chaotic inflation model in supergravity, for which the predicted spectral index and tensor-to-scalar ratio can lie within the 1 sigma region allowed by the Planck results. Most importantly, the predicted…

High Energy Physics - Phenomenology · Physics 2015-06-16 Kazunori Nakayama , Fuminobu Takahashi , Tsutomu T. Yanagida