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Related papers: Tachyon inflation with steep potentials

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We present a minimal axion inflation model which can generate a large tensor-to-scalar ratio while remaining sub-Planckian. The modulus of a complex scalar field $\Phi$ with a $\lambda |\Phi|^4$ potential couples directly to the gauge field…

High Energy Physics - Phenomenology · Physics 2015-06-22 John McDonald

The single scalar field inflationary models that lead to scalar and tensor perturbation spectra with amplitudes varying in direct proportion to one another are reconstructed by solving the Stewart-Lyth inverse problem to next-to-leading…

Astrophysics · Physics 2009-11-07 C. A. Terrero-Escalante , James E. Lidsey , Alberto A. Garcia

The emergent model in the context of loop quantum cosmology with a tachyon scalar field is studied. We find that there is a center equilibrium point in the semiclassical region and a saddle point in the classical region. If the potential of…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-28 Puxun Wu , Shuang Nan Zhang , Hongwei Yu

We investigate the power-law, intermediate, and logamediate inflationary models in the framework of DBI non-canonical scalar field with constant sound speed. In the DBI setting, we first represent the power spectrum of both scalar density…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-20 Roonak Amani , Kazem Rezazadeh , Asrin Abdolmaleki , Kayoomars Karami

We discuss implications of the latest BICEP/Keck data release for inflationary models, with particular emphasis on scalar fields with non-canonical Lagrangians of the type ${\cal L} = X^\alpha - V(\phi)$. The observational upper bound on…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-20 Swagat S. Mishra , Varun Sahni

We investigate the warm inflation condition in loop quantum cosmology. In our consideration, the system is described by a tachyon field interacted with radiation. The exponential potential function, $V(\phi)=V_0…

General Relativity and Quantum Cosmology · Physics 2011-06-16 Kui Xiao , Jian-Yang Zhu

We study Quadratic Inflation with the inflaton field $\phi$ coupled non-minimally to the curvature scalar $R$, so that the potential during inflation is of the form $V\propto m^2\phi^2+\xi R\phi^2$. We show that with a suitable choice of…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-13 Tommi Tenkanen

Nonminimally coupled inflation models based on a nonminimal coupling $\xi \phi^{2} R$ and a $\phi^{4}$ potential are in excellent agreement with the scalar spectral index observed by Planck. Here we consider the modification of these models…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Jinsu Kim , John McDonald

Models of inflationary cosmology based on spontaneous symmetry breaking typically suffer from the shortcoming that the symmetry breaking scale is driven to nearly the Planck scale by observational constraints. In this paper we investigate…

High Energy Physics - Phenomenology · Physics 2009-10-28 William H. Kinney , K. T. Mahanthappa

In this paper we will analyse the constraints on a sub-Planckian excursion of a single inflaton field, which would yield a large tensor to scalar ratio, while explaining the temperature anisotropy of the cosmic microwave background (CMB)…

High Energy Physics - Theory · Physics 2014-04-01 Sayantan Choudhury , Anupam Mazumdar

We use the PLANCK 2018 and the WMAP data to constraint inflation models driven by a scalar field $\phi$ in the presence of the non-minimal scalar-curvature mixing term $\frac{1}{2}\xi R \phi^2$. We consider four distinct scalar field…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 Payel Sarkar , Ashmita , Prasanta Kumar Das

Combining Planck CMB temperature [1] and BICEP2 B-mode polarization data [2,3] we show qualitatively that, assuming inflationary consistency relation, the power-law form of the scalar primordial spectrum is ruled out at more than $3\sigma$…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-17 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

The combination of the data from the Dark Energy Spectroscopic Instrument (DESI) with the recent measurements from the Atacama Cosmology Telescope (ACT) indicate that the scalar spectral index \( n_s \) has a larger value than the Planck…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-02 Jureeporn Yuennan , Farruh Atamurotov , Phongpichit Channuie

We consider the mimetic tachyon model in the Lagrange multiplier approach. We study both the linear and non-linear perturbations and find the perturbation and non-gaussianity parameters in this setup. By adopting two types of the scale…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-05 Narges Rashidi , Kourosh Nozari

Recent cosmological observations are in good agreement with the scalar spectral index $n_s$ with $n_s-1\sim -2/N$, where $N$ is the number of e-foldings. Quadratic chaotic model, Starobinsky model and Higgs inflation or $\alpha$-attractors…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-03 Takeshi Chiba

Recently we have studied in great detail a model of Hybrid Natural Inflation (HNI) by constructing two simple effective field theories. These two versions of the model allow inflationary energy scales as small as the electroweak scale in…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-13 Gabriel German , Alfredo Herrera-Aguilar , Juan Carlos Hidalgo , Roberto A. Sussman , Jose Tapia

We present two families of multi-field potentials that support inflation while satisfying the refined de Sitter and the distance swampland conjectures. Both families feature Planck-compatible phenomenology. The first is a helix-type…

High Energy Physics - Theory · Physics 2020-04-29 Vikas Aragam , Sonia Paban , Robert Rosati

In this paper, we examine the possible realization of a new family of inflation called "shaft inflation" by assuming the modified Chaplygin gas model and tachyon scalar field. We also consider the special form of dissipative coefficient as…

General Relativity and Quantum Cosmology · Physics 2017-03-08 Abdul Jawad , Amara Ilyas , Shamaila Rani

Motivated by the idea that inflation occurs at the GUT symmetry breaking scale, in this paper we construct a new class of large field inflaton potentials where the inflaton starts with a power law potential; after initial period of relative…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

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