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A single field inflation based on a supergravity model with a shift symmetry and $U(1)$ extension of the MSSM is analyzed. We show that one of the real components of the two $U(1)$ charged scalar fields plays the role of inflaton {with} an…

High Energy Physics - Phenomenology · Physics 2015-10-28 Lucien Heurtier , Shaaban Khalil , Ahmad Moursy

We describe a way to construct supergravity models with an arbitrary inflaton potential V ({\phi}) and show that all other scalar fields in this class of models can be stabilized at the inflationary trajectory by a proper choice of the…

High Energy Physics - Theory · Physics 2011-02-18 Renata Kallosh , Andrei Linde , Tomas Rube

We present novel realizations of E- and T-model inflation within Supergravity which are largely associated with the existence of a pole of order one and two respectively in the kinetic term of the inflaton superfield. This pole arises due…

High Energy Physics - Phenomenology · Physics 2022-12-06 C. Pallis

Cosmological inflation gives a natural answer for a variety of cosmological questions, including the horizon problem, the flatness problem, and others. However, inflation yields new questions relating to the flatness of the inflaton…

High Energy Physics - Phenomenology · Physics 2009-11-10 David E. Kaplan , Neal Weiner

We consider models of inflation in supergravity with a shift symmetry. We focus on models with one moduli and one inflaton field. The presence of this symmetry guarantees the existence of a flat direction for the inflaton field. Mildly…

High Energy Physics - Theory · Physics 2009-11-11 Philippe Brax , Jerome Martin

A second order pole in the scalar kinetic term can lead to a class of inflation models with universal predictions referred to as pole inflation or $\alpha$-attractors. While this kinetic structure is ubiquitous in supergravity effective…

High Energy Physics - Theory · Physics 2019-03-11 Mafalda Dias , Jonathan Frazer , Ander Retolaza , Marco Scalisi , Alexander Westphal

In string-inspired supergravity theory, K\"{a}hler metric of chiral matter fields often has a pole. Such K\"{a}hler metric is interesting from the viewpoint of the framework of the pole inflation, where the scalar potential can be stretched…

High Energy Physics - Theory · Physics 2019-12-06 Tatsuo Kobayashi , Osamu Seto , Takuya H. Tatsuishi

We consider a class of helical phase inflation models from the ${\mathcal N}=1$ supergravity where the phase component of a complex field acts as an inflaton. This class of models avoids the eta problem in supergravity inflation due to the…

High Energy Physics - Phenomenology · Physics 2020-09-18 Mudassar Sabir , Waqas Ahmed , Yungui Gong , Tianjun Li , Jiong Lin

We develop four-parameter supergravity models of inflation and dark energy, constrained so that ${\delta\rho\over \rho}$, $n_s$ and the cosmological constant $\Lambda $ take their known observable values, but where the mass of gravitino…

High Energy Physics - Theory · Physics 2015-07-06 John Joseph M. Carrasco , Renata Kallosh , Andrei Linde

The distinctive features of single field inflationary models with non-minimal kinetic terms, like Dirac-Born-Infeld and k-inflation, can be captured by more familiar multiple field inflationary systems of the type that typically arise in…

High Energy Physics - Theory · Physics 2014-11-20 Andrew J. Tolley , Mark Wyman

We study inflation driven by a slow-rolling inflaton field, characterised by a quadratic potential, and incorporating radiative corrections within the context of supergravity. In this model the energy scale of inflation is not overly…

High Energy Physics - Phenomenology · Physics 2011-02-16 Gabriel German , Graham Ross , Subir Sarkar

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

The potential during inflation must be very flat in, at least, the direction of the inflaton. In renormalizable global supersymmetry, flat directions are ubiquitous, but they are not preserved in a generic supergravity theory. It is known…

High Energy Physics - Theory · Physics 2009-09-29 Mary K. Gaillard , David H. Lyth , Hitoshi Murayama

We construct a natural inflation model in supergravity where the inflaton is identified with a modulus field possessing a shift symmetry. The superpotential for the inflaton is generated by meson condensation due to strong dynamics with…

High Energy Physics - Phenomenology · Physics 2015-06-22 Keisuke Harigaya , Masahiro Ibe , Tsutomu T. Yanagida

We show how observations of the perturbation spectra produced during inflation may be used to constrain the parameters of general scalar-tensor theories of gravity, which include both an inflaton and dilaton field. An interesting feature of…

General Relativity and Quantum Cosmology · Physics 2016-08-24 Juan Garcia-Bellido , David Wands

We compute in detail how deviations from Einstein gravity at the inflation energy scale could appear as non-Gaussian features in the sky. To illustrate this we use multi-field $\alpha-$attractor models in the framework of supergravity to…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-14 Nicola Bartolo , Domenico Matteo Bianco , Raul Jimenez , Sabino Matarrese , Licia Verde

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 consider "new inflation" inflationary models at small fields, embedded in minimal ${\cal N}=1$ supergravity with a single chiral superfield. Imposing a period of inflation compatible with experiment severely restricts possible models,…

High Energy Physics - Theory · Physics 2016-10-12 Heliudson Bernardo , Horatiu Nastase

We study models of inflation where the inflaton corresponds to a flat direction in field space and its mass term is generated by gravity mediated soft supersymmetry breaking at high scale. Assuming the inflaton to have non negligible…

High Energy Physics - Phenomenology · Physics 2007-05-23 Laura Covi

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