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Related papers: Tachyon constant-roll inflation

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We study a single field inflationary model modified by a non-minimal coupling term between the Ricci scalar $R$ and the scalar field $\varphi$ in the context of constant-roll inflation. The first-order formalism is used to analyse the…

General Relativity and Quantum Cosmology · Physics 2021-08-11 Mehdi Shokri , Jafar Sadeghi , Mohammad Reza Setare , Salvatore Capozziello

We present a tachyonic field inflationary model in a teleparallel framework. We show that tachyonic coupled with the f(T) gravity model can describe the inflation era in which f(T) is an arbitrary function of torsion scalar T. For this…

General Relativity and Quantum Cosmology · Physics 2020-02-24 Amin Rezaei Akbarieh , Yousef Izadi

Plateau inflation is an experimentally consistent framework in which the scale of inflation can be kept relatively low. Close to the edge of the plateau, scalar perturbations are subject to a strong tachyonic instability. Tachyonic…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-24 Eemeli Tomberg , Hardi Veermäe

The model of inflation with a single tachyon field generates larger anisotropy and has difficulties in describing the formation of the Universe . In this paper we consider a model with multi tachyon fields and study the assisted…

High Energy Physics - Phenomenology · Physics 2009-11-07 Yun-Song Piao , Rong-Gen Cai , Xinmin Zhang , Yuan-Zhong Zhang

Rapid-turn slow-roll inflationary trajectories have been shown to be an attractor in two-field models, provided the turn rate is near constant and larger than the slow-roll parameters. These trajectories can produce primordial spectra…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-06 Raul Wolters , Oksana Iarygina , Ana Achucarro

Warm inflationary universe models in a tachyon field theory are studied. General conditions required for these models to be realizable are derived and discussed. We describe scalar perturbations (in the longitudinal gauge) and tensor…

Astrophysics · Physics 2009-11-11 R. Herrera , S. del Campo , C. Campuzano

In this work, we investigate how a smooth transition from a constant-roll to a slow-roll inflationary era may be realized, in the context of a canonical scalar field theory. We study in some detail the dynamical evolution of the…

General Relativity and Quantum Cosmology · Physics 2018-02-14 V. K. Oikonomou

In this work we shall investigate the phenomenological implications of the constant-roll condition on a $k$-Inflation theory of gravity. The latter theories are particularly promising, since these remained robust to the results of GW170817,…

General Relativity and Quantum Cosmology · Physics 2020-01-29 S. D. Odintsov , V. K. Oikonomou

We study the slow-roll regime of two field inflation, in which the two fields are also coupled through their kinetic terms. Such Lagrangians are motivated by particle physics and by scalar-tensor theories studied in the Einstein frame. We…

Astrophysics · Physics 2009-11-11 Fabrizio Di Marco , Fabio Finelli

In this paper we show that the dynamics associated with slow-roll models of inflation can be investigated through a method called deformation procedure. Using the latter, we explicitly derive an expression linking two slow-roll inflationary…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Jamilton Rodrigues , Marcos Souza

Assuming that the e-folding number is just determined by the change of the scale factor, the tachyonic inflation theory in LQC has been discussed. Considering the tachyon field with exponential potential and inverse quadratic potential, we…

General Relativity and Quantum Cosmology · Physics 2014-12-16 Kui Xiao , Xiao-Kai He , Fei Huang , Jian-Yang Zhu

In this work, we study a constant-roll inflationary model in the Palatini formalism using modified gravity. Here our action consists a non-minimal coupling of a scalar field $\phi$ with Ricci scalar $R$ in a general form of $f(R,\phi)$.…

General Relativity and Quantum Cosmology · Physics 2023-04-19 Sukanta Panda , Arun Rana , Rahul Thakur

We provide an explicit solution representing an anisotropic power law inflation within the framework of rolling tachyon model. This is generated by allowing a non-minimal coupling between the tachyon and the world-volume gauge field on…

High Energy Physics - Theory · Physics 2012-01-25 Samrat Bhowmick , Sudipta Mukherji

In this work, we propose a string-inspired two fields inflation model to address the fine-tuning problem that the standard inflation model suffers. The fast-rolling tachyon $\mathcal{T}$ originated from the D-brane and anti-D-brane pair…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-01 Changhong Li , Hao Gong , Yeuk-kwan Edna Cheung

We investigate the constant-roll inflation with non-minimally kinetic coupling to the Einstein tensor. With the slow-roll parameter $\eta_\phi = -\ddot{\phi}/(H\dot{\phi})$ being a constant, we calculate the power spectra for scalar and…

General Relativity and Quantum Cosmology · Physics 2024-07-22 Jie Liu , Yungui Gong , Zhu Yi

Starting from the idea of realising constant roll inflation in string theory we develop the constant roll formalism for two scalar fields. We derive the two-field potential which is compatible with a constant roll regime and discuss…

High Energy Physics - Theory · Physics 2019-11-13 Andrei Micu

A study of the slow-roll inflation for an exponential potential in the frame of the scalar-tensor theory is performed, where non-minimal kinetic coupling to curvature and non-minimal coupling of the scalar field to the Gauss-Bonnet…

High Energy Physics - Theory · Physics 2019-09-24 L. N. Granda , D. F. Jimenez

By studying the chameleon model during inflation, we investigate whether it can be a successful inflationary model, wherein we employ the common typical potential usually used in the literature. Thus, in the context of the slow-roll…

General Relativity and Quantum Cosmology · Physics 2018-04-13 Nasim Saba , Mehrdad Farhoudi

We summarize our work on a consistency condition for inflation in two-field cosmological models, in the regime of rapid turn and third-order slow roll. To ensure a sustained inflationary period of this type, one needs to satisfy a certain…

High Energy Physics - Theory · Physics 2025-04-09 Lilia Anguelova , Calin Iuliu Lazaroiu

In slow roll inflation, the running of the spectral tilt is generically proportional to the square of the deviation from scale invariance, $\alpha_s \propto (n_s-1)^2$, and it is therefore currently undetectable. We present a mechanism able…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Marco Peloso , Lorenzo Sorbo , Gianmassimo Tasinato