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Related papers: Reconstructing k-inflation from $n_s(N)$ and rehea…

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This paper describes a general program for deriving the action of single field inflation models with nonstandard kinetic energy terms using CMBR power spectrum data. This method assumes that an action depends on a set of undetermined…

Astrophysics · Physics 2009-06-23 Christopher S. Gauthier , Ratindranath Akhoury

In this work, we study the early universe inflation and the post-inflation reheating era employing an inverse tangent potential of the form $V=V_0 \cdot[tan^{-1}(\frac{\kappa \phi}{m_p})]^2$, where $\kappa$ is a free parameter of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Mayur Abhisheki , Prasanta Kumar Das

We study the two-phase scenario following inflation, where the initial step is preheating, accompanied by a step of perturbative reheating at which inflaton field decays transferring all of its energy to create relativistic particles, the…

General Relativity and Quantum Cosmology · Physics 2021-05-03 Khalil El Bourakadi

A new model for inflation using modified gravity in the Palatini formalism is constructed. Here non-minimal coupling of scalar field h with the curvature R as a general function f(R,h) is considered. Explicit inflation models for some…

General Relativity and Quantum Cosmology · Physics 2021-05-19 Nayan Das , Sukanta Panda

We study observational viability of Natural Inflation with a tachyon field as inflaton. By obtaining the main perturbation parameters in this model, we perform a numerical analysis on the parameter space of the model and in confrontation…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Narges Rashidi , Kourosh Nozari , Oyvind Gron

We locally reconstruct the inflationary potential by using the current constraints on $r$ and $n_{\rm s}$ from BICEP2 data. Assuming small and negligible $\alpha_{\rm s}$, the inflationary potential is approximately linear in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Yin-Zhe Ma , Yi Wang

We explore a square-law k-inflation using the Hamilton-Jacobi approach. Focusing on scenarios where the Hubble parameter exhibits a power-law dependence on the k-field, our analysis encompasses the computations of crucial observables, such…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Ming Liu , Tong-Yu He , Bohai Chen , Zhan-Wen Han , Rong-Jia Yang

The study of reheating in inflationary models is crucial for understanding the early universe and gaining insights into inflationary dynamics and parameters. The reheating temperature $T_{re}$ and the duration of the reheating phase,…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-02 Gabriel German , Juan Carlos Hidalgo , Luis E. Padilla

In this work we revisit $\alpha$-Starobinsky inflation, also know as $E$-model, in the light of current CMB and LSS observations. The inflaton potential in the Einstein frame for this model contains a parameter $\alpha$ in the exponential,…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-11 Saisandri Saini , Akhilesh Nautiyal

We discuss the theoretical framework behind reconstruction of a generic class of inflationary potentials for canonical single-field slow-roll inflation in a model-independent fashion. The Non-Bunch Davies (NBD) initial condition is an…

General Relativity and Quantum Cosmology · Physics 2024-10-17 Sayantan Choudhury

After Planck 2013, a broad class of inflationary models called \alpha-attractors was developed which has universal observational predictions. For small values of the parameter \alpha, the models have good consistency with the recent CMB…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Mehdi Eshaghi , Moslem Zarei , Nematollah Riazi , Ahmad Kiasatpour

Within the class of inflationary models, k-inflation represents the most general single field framework that can be associated with an effective quadratic action for the curvature perturbations and a varying speed of sound. The incoming…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-04 Jerome Martin , Christophe Ringeval , Vincent Vennin

Current observations indicate that an inverse exponential form of the inflaton potential provides an excellent description of single-field inflation. This potential fits the SPA$+$BK$+$DESI data sets well with in the $1\sigma$ bound in the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-03 Md. Wali Hossain

In this paper, we reconstruct viable inflationary models by starting from spectral index and tensor-to-scalar ratio from Planck observations. We analyze three different kinds of models: scalar field theories, fluid cosmology and…

General Relativity and Quantum Cosmology · Physics 2015-09-21 Ratbay Myrzakulov , Lorenzo Sebastiani , Sergio Zerbini

The Atacama Cosmology Telescope (ACT) has recently reported updated measurements of the scalar spectral index $n_s$, revealing a tension with the predictions of many conventional inflationary models. In this work, we adopt a…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Zhu Yi , Xingzhi Wang , Qing Gao , Yungui Gong

We eliminate the parameters originally present in models of inflation of the $\alpha$-attractor type in favor of the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$. We then write expressions for the number of $e$-folds…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-02 Gabriel German

We review the relation between the inflationary potential and the spectra of density (scalar) perturbations and gravitational waves (tensor perturbations) produced, with particular emphasis on the possibility of reconstructing the inflaton…

We systematically study the renormalizable three-term polynomial inflation in the supersymmetric and non-supersymmetric models. The supersymmetric inflaton potentials can be realized in supergravity theory, and only have two independent…

High Energy Physics - Phenomenology · Physics 2015-10-26 Tianjun Li , Zheng Sun , Chi Tian , Lina Wu

In this work we shall study $k$-inflation theories with non-minimal coupling of the scalar field to gravity, in the presence of only a higher order kinetic term of the form $\sim \mathrm{const}\times X^{\mu}$, with…

General Relativity and Quantum Cosmology · Physics 2021-01-05 V. K. Oikonomou

It is investigated the reconstruction during the slow-roll inflation in the most general class of scalar-torsion theories whose Lagrangian density is an arbitrary function $f(T,\phi)$ of the torsion scalar $T$ of teleparallel gravity and…

General Relativity and Quantum Cosmology · Physics 2021-08-17 Manuel Gonzalez-Espinoza , Ramón Herrera , Giovanni Otalora , Joel Saavedra