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Related papers: Self-tuning inflation

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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 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 propose the Starobinsky-type inflationary model in the matter-coupled $N=1$ four-dimensional supergravity with the massive vector multiplet that has inflaton (scalaron) and goldstino amongst its field components, whose action includes…

High Energy Physics - Theory · Physics 2019-05-22 Hiroyuki Abe , Yermek Aldabergenov , Shuntaro Aoki , Sergei V. Ketov

We review the realization of Starobinsky-type inflation within induced-gravity Supersymmetric (SUSY) and non-SUSY models. In both cases, inflation is in agreement with the current data and can be attained for subplanckian values of the…

High Energy Physics - Phenomenology · Physics 2017-06-20 C. Pallis , N. Toumbas

The Starobinsky model of inflation, consistent with Planck 2015, has a peculiar form of the action, which contains the leading Einstein term $R$, the $R^2$ term with a huge coefficient, and negligible higher-order terms. We propose an…

High Energy Physics - Theory · Physics 2016-12-13 Takehiko Asaka , Satoshi Iso , Hikaru Kawai , Kazunori Kohri , Toshifumi Noumi , Takahiro Terada

We introduce super exponential inflation ($\omega < -1$) from a 5D Riemann-flat canonical metric on which we make a dynamical foliation. The resulting metric describes a super accelerated expansion for the early universe well-known as super…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Mauricio Bellini

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

In most current models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, the period of inflation lasts so long that, at the beginning of the inflationary period, the physical wavelengths of…

High Energy Physics - Theory · Physics 2008-11-26 Jerome Martin , Robert H. Brandenberger

We have presented previously a general treatment of Starobinsky-like inflation in no-scale supergravity where the tensor-to-scalar ratio $r = 3(1 - n_s)^2$, and $n_s$ is the tilt of the scalar perturbations. In particular, we have shown how…

High Energy Physics - Theory · Physics 2019-10-02 John Ellis , Dimitri V. Nanopoulos , Keith A. Olive , Sarunas Verner

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

A scenario with two subsequent periods of inflationary expansion in the very early universe is examined. The model is based on a potential motivated by symmetries being found in field theory at high energy. For various parameter sets of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 Simon Schettler , Jurgen Schaffner-Bielich

In the context of (4+d)-dimensional general relativity, we propose an inflationary scenario wherein 3 spatial dimensions grow large, while d extra dimensions remain small. Our model requires that a self-interacting d-form acquire a vacuum…

High Energy Physics - Theory · Physics 2009-11-10 C. Armendariz-Picon , Vikram Duvvuri

We study the problem of obtaining de Sitter and inflationary vacua from dimensional reduction of double field theory (DFT) on nongeometric string backgrounds. In this context, we consider a new class of effective potentials that admit…

High Energy Physics - Theory · Physics 2016-05-05 Falk Hassler , Dieter Lust , Stefano Massai

We investigate the initiation of cosmic inflation, in full numerical relativity, from pre-inflationary scenarios with large tensor and vector fluctuations in the metric. These settings are characterized by having large values in the Weyl…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-04 Cristian Joana

We derive the scalar potential in four spacetime dimensions from an eight-dimensional $(R+\gamma R^4-2\Lambda-F_4^2)$ gravity model in the presence of the 4-form $F_4$, with the (modified gravity) coupling constant $\gamma$ and the…

High Energy Physics - Theory · Physics 2018-01-03 Hiroshi Nakada , Sergei V. Ketov

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 examine some inflationary models based on modifications of gravity in the light of Planck 2015 data, such as the generalised Chaplygin inspired inflation, models based in $N=1$ supergravity and braneworld scenarios. We also show that,…

High Energy Physics - Theory · Physics 2018-06-06 Cláudio Gomes , Orfeu Bertolami , João G. Rosa

We describe an induced inflation, which refers to a class of inflationary models with a generalized non-minimal coupling $\xi g(\phi) R$ and a specific scalar potential. The defining property of these models is that the scalar field takes a…

High Energy Physics - Theory · Physics 2015-06-22 Renata Kallosh , Andrei Linde , Diederik Roest

A nonsingular deflationary cosmology driven by adiabatic matter creation is proposed. In this scenario there is no preinflationary stage as happens in conventional inflationary models. Deflation starts from a de Sitter spacetime…

General Relativity and Quantum Cosmology · Physics 2009-10-28 J. A. S. Lima , L. R. W. Abramo

We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, $w$, during the epoch of inflaton decay, the reheating temperature, $T_{\rm reh}$, and the…

High Energy Physics - Phenomenology · Physics 2015-08-06 John Ellis , Marcos A. G. Garcia , Dimitri V. Nanopoulos , Keith A. Olive