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We investigate inflationary magnetogenesis in a scenario where conformal invariance of electromagnetism is broken through a \emph{non-minimal Yukawa-like coupling between the inflaton and the Ricci scalar}. We account for electromagnetic…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-14 Orlando Luongo , Antonino Giacomo Marino , Tommaso Mengoni

We consider the non-supersymmetric models of chaotic (driven by a quadratic potential) and hybrid inflation, taking into account the minimal possible radiative corrections to the inflationary potential. We show that two simple coupling…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 C. Pallis

Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor…

High Energy Physics - Theory · Physics 2008-11-26 Lev Kofman , Shinji Mukohyama

Once quantum corrections are taken into account, the strong coupling limit of the $\xi$-attractor models (in metric gravity) might depart from the usual Starobinsky solution and move into linear inflation. Furthermore, it is well known that…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-18 Antonio Racioppi

We consider a scenario in which the inflaton $\phi$ is a pseudoscalar field non-minimally coupled to gravity through a term of the form ${\cal X} R \phi^2$. The pseudoscalar is also coupled to a $U(1)$ gauge field (or an ensemble of ${\cal…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-17 Juan P. Beltrán Almeida , Nicolás Bernal

It is a longstanding desire of cosmologists, and particle physicists as well, to connect inflation to low energy physics, culminating, for instance, in what is known as Higgs inflation. The condition for the standard Higgs boson playing the…

High Energy Physics - Phenomenology · Physics 2017-11-15 J. G. Ferreira , C. A. de S. Pires , J. G. Rodrigues , P. S. Rodrigues da Silva

We consider a modified gravity framework for inflation by adding to the Einstein-Hilbert action a direct $f(\phi)T$ term, where $\phi$ is identified as the inflaton and $T$ is the trace of the energy-momentum tensor. The framework goes to…

General Relativity and Quantum Cosmology · Physics 2022-02-23 Xinyi Zhang , Che-Yu Chen , Yakefu Reyimuaji

Single field inflationary models are investigated within Palatini quadratic gravity represented by $R+\alpha R^2$ along with a non-minimal coupling of the form $f(\phi) R$ between the inflaton field $\phi$ and the gravity. The treatment is…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-15 Mahmoud AlHallak

We find new realizations of Volkov-Akulov-Starobinsky supergravity, i.e. Starobinsky inflationary models in supergravity coupled to a nilpotent superfield describing Volkov-Akulov goldstino. Our constructions are based on the no-scale…

High Energy Physics - Theory · Physics 2020-04-23 Yermek Aldabergenov

In this work we introduce a new plateau-like inflationary model including a quadratic scalar potential coupled non-minimally to gravity. This potential has a dominant constant energy density at early times which can realize successful…

High Energy Physics - Theory · Physics 2015-11-30 Mehdi Eshaghi , Moslem Zarei , Nematollah Riazi , Ahmad Kiasatpour

We study a new anisotropic inflation model, with an inflaton field nonminimally coupled with the gravity and a vector field. We find that the anisotropic attractor solution exists not only in the weak curvature coupling limit, but more…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Bin Chen , Zhuang-wei Jin

We examine the inflationary modes in the cubic curvature theories in the context of asymptotically safe gravity. On the phase space of the Hubble parameter, there exists a critical point which corresponds to the slow-roll inflation in…

General Relativity and Quantum Cosmology · Physics 2012-08-09 Sungwook E. Hong , Young Jae Lee , Heeseung Zoe

We investigate the predictions of inflation models with a non-minimal coupling to gravity for inflationary observables such as the spectral index and tensor-to-scalar ratio in a general setting. We argue that, depending on the relation…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-13 Tatsuki Kodama , Tomo Takahashi

A new setup of cosmic inflation with a periodic inflaton potential and conformal factor is discussed in the metric and Palatini formulations of gravity. As a concrete example, we focus on a natural-inflation-like inflaton potential, and…

General Relativity and Quantum Cosmology · Physics 2019-03-21 Ryusuke Jinno , Kunio Kaneta , Kin-ya Oda , Seong Chan Park

An N=1 Poincare supergravity action, suitable for describing the Starobinsky inflation, is proposed. It extends f(R) gravity to supergravity in its old-minimal version. The action is parametrized by a single holomorphic potential and a…

High Energy Physics - Theory · Physics 2013-12-30 Sergei V. Ketov

We construct an inflation model with inflaton non-minimally coupled to gravity on a warped DGP brane. Using an exponential potential, we calculate scalar power spectrum, spectral index and the running of the spectral index. We show that for…

High Energy Physics - Theory · Physics 2009-06-11 Kourosh Nozari , Behnaz Fazlpour

We reconsider an inflationary model that inflaton field is non-minimally coupled to gravity. We study parameter space of the model up to the second ( and in some cases third ) order of the slow-roll parameters. We calculate inflation…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Kourosh Nozari , S. Shafizadeh

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

In this paper, we employ the Palatini formalism to investigate the dynamics of large-field inflation using a renormalizable polynomial inflaton potential in the context of $f(R,\phi)$ gravity. Assuming instant reheating, we make a…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-20 Nilay Bostan , Canan Karahan , Ozan Sargın

The supersymmetric extension of "Starobinsky" $R+\alpha R^2$ models of inflation is particularly simple in the "new minimal" formalism of supergravity, where the inflaton has no scalar superpartners. This paper is devoted to matter…

High Energy Physics - Theory · Physics 2015-06-22 S. Ferrara , M. Porrati