English
Related papers

Related papers: Beyond the Starobinsky model for inflation

200 papers

Analytic infinite derivative (AID) non-local quadratic curvature gravity in Weyl basis is known to be ghost free, superrenormalizable or finite and perturbatively Unitary and as such it is Ultra-Violet (UV) complete. Recently $R+R^2$…

High Energy Physics - Theory · Physics 2018-10-08 K. Sravan Kumar , Leonardo Modesto

In the new-minimal supergravity formulation we present the embedding of the $R+R^2$ Starobinsky model of inflation. Starting from the superspace action we perform the projection to component fields and identify the Starobinsky model in the…

High Energy Physics - Theory · Physics 2015-09-02 Fotis Farakos

We introduce a modification of the Starobinsky model in the form of an additional cubic Ricci scalar curvature term $\sim \alpha R^3$, scaled by a dimensionless parameter $\alpha$, with the resulting inflaton potential being the standard…

General Relativity and Quantum Cosmology · Physics 2025-09-23 Ioannis D. Gialamas , Theodoros Katsoulas , Kyriakos Tamvakis

We have found numerically initial conditions in the $(R, H)$ plane leading to a successful Starobinsky inflation in $R+R^2$ gravity for a isotropic metrics with positive spatial curvature. Trajectories can reach inflation regime either…

General Relativity and Quantum Cosmology · Physics 2023-11-03 Daniel Müller , Alexey Toporensky

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

Thanks to the Planck Collaboration, we know the value of the scalar spectral index of primordial fluctuations with unprecedented precision. In addition, the joint analysis of the data from Planck, BICEP2, and KEK has further constrained the…

General Relativity and Quantum Cosmology · Physics 2015-06-24 Massimiliano Rinaldi , Guido Cognola , Luciano Vanzo , Sergio Zerbini

We point out that the ability of some models of inflation, such as Higgs inflation and the universal attractor models, in reproducing the available data is due to their relation to the Starobinsky model of inflation. For large field values,…

High Energy Physics - Theory · Physics 2014-03-05 Alex Kehagias , Azadeh Moradinezhad Dizgah , Antonio Riotto

We consider an extension of the Starobinsky model, whose parameters are functions of an extra scalar field. Our motivation is to test the robustness (or sensitivity) of the Starobinsky inflation against mixing scalaron with another (matter)…

High Energy Physics - Theory · Physics 2016-02-17 Sho Kaneda , Sergei V. Ketov

We investigate the cosmological inflation in a class of supergravity models that are generalizations of non-supersymmetric $R^2$ models. Although such models have been extensively studied recently, especially after the launch of the PLANCK…

High Energy Physics - Theory · Physics 2015-06-23 G. A. Diamandis , B. C. Georgalas , K. Kaskavelis , P. Kouroumalou , A. B. Lahanas , G. Pavlopoulos

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

Starobinsky's $R+\alpha R^2$ inflation provides a compelling one-parameter inflationary model that is supported by current cosmological observations. However, at the same order in spacetime derivatives as the $R^2$ term, an effective theory…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Eugenio Bianchi , Mauricio Gamonal

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 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

In the context of gravity's rainbow, we study the deformed Starobinsky model in which the deformations take the form $f(R)\sim R^{2(1-\alpha)}$, with $R$ the Ricci scalar and $\alpha$ a positive parameter. We show that the spectral index of…

General Relativity and Quantum Cosmology · Physics 2019-06-18 Phongpichit Channuie

We consider initial conditions leading to Starobinsky inflation in the general quadratic gravity, where the action of the theory contains one more curvature square invariant in addition to $R^2$. We have chosen corresponding coefficients in…

General Relativity and Quantum Cosmology · Physics 2025-05-09 Daniel Muller , Alexey Toporensky

The Starobinsky model, considered in the framework of the Palatini formalism, in contrast to the metric formulation, does not provide us with a model for inflation, due to the absence of a propagating scalar degree of freedom that can play…

General Relativity and Quantum Cosmology · Physics 2018-11-28 I. Antoniadis , A. Karam , A. Lykkas , K. Tamvakis

In this paper, we build upon the successes of the ultraviolet (UV) completion of the Starobinsky model of inflation. This involves an extension of the Einstein-Hilbert term by an infinite covariant derivative theory of gravity, which is…

General Relativity and Quantum Cosmology · Physics 2017-11-15 James Edholm

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 Starobinsky model of cosmological inflation in four spacetime dimensions is reviewed with the emphasis on impact of quantum gravity corrections. As a specific example of the quantum corrections, the Grisaru-Zanon quartic curvature terms…

General Relativity and Quantum Cosmology · Physics 2025-01-09 Shunsuke Toyama , Sergei V. Ketov

We revisit the old (fourth-order or quadratically generated) gravity model of Starobinsky in four space-time dimensions, and derive the (inflaton) scalar potential in the equivalent scalar-tensor gravity model via a Legendre-Weyl transform.…

High Energy Physics - Theory · Physics 2010-12-09 S. Kaneda , S. V. Ketov , N. Watanabe