Dynamics of warm power-law plateau inflation with a generalized inflaton decay rate: predictions and constraints after Planck 2015

Abdul Jawad; Nelson Videla; Faiza Gulshan

doi:10.1140/epjc/s10052-017-4846-1

EPJ

a
b
c
d
e
ap
st
h
plus
ds
pv
ti
qt
am
n

2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2017) 77: 271
https://doi.org/10.1140/epjc/s10052-017-4846-1

Regular Article - Theoretical Physics

Dynamics of warm power-law plateau inflation with a generalized inflaton decay rate: predictions and constraints after Planck 2015

Abdul Jawad¹, Nelson Videla²^* and Faiza Gulshan³

¹ Department of Mathematics, COMSATS Institute of Information Technology, Lahore, 54000, Pakistan
² Departamento de Física, FCFM, Universidad de Chile, Blanco Encalada 2008, Santiago, Chile
³ Department of Mathematics, Lahore Leads University, Lahore, 54000, Pakistan

^* e-mail: nelson.videla@ing.uchile.cl

Received: 20 January 2017
Accepted: 21 April 2017
Published online: 29 April 2017

Abstract

In the present work, we study the consequences of considering a new family of single-field inflation models, called power-law plateau inflation, in the warm inflation framework. We consider the inflationary expansion is driven by a standard scalar field with a decay ratio $\Gamma$ having a generic power-law dependence with the scalar field $\phi$ and the temperature of the thermal bath T given by $\Gamma (\phi ,T)=C_{\phi }\frac{T^a}{\phi ^{a-1}}$ . Assuming that our model evolves according to the strong dissipative regime, we study the background and perturbative dynamics, obtaining the most relevant inflationary observable as the scalar power spectrum, the scalar spectral index and its running and the tensor-to-scalar ratio. The free parameters characterizing our model are constrained by considering the essential condition for warm inflation, the conditions for the model evolves according to the strong dissipative regime and the 2015 Planck results through the $n_\mathrm{s}$ –r plane. For completeness, we study the predictions in the $n_\mathrm{s}$ – $\mathrm{d}n_\mathrm{s}/\mathrm{d}\ln k$ plane. The model is consistent with a strong dissipative dynamics and predicts values for the tensor-to-scalar ratio and for the running of the scalar spectral index consistent with current bounds imposed by Planck and we conclude that the model is viable.