SearcharxivSearch

arXiv subjects

Sabina Yeasmin

Publications and source records attributed to Sabina Yeasmin.

4 recordsLinked to original sources

Warm Inflation in a Braneworld Scenario

In the literature, many warm inflationary models are formulated. In this piece of work, a warm inflationary model in the braneworld scenario is studied, considering constant and variable dissipation coefficients. Performance of the model has been considered in both strong and weak dissipative regimes. We study the dynamics of this scenario under slow-roll approximation and estimate cosmological observables, viz., the spectral index and tensor-to-scalar ratio. In order to constrain the parameters in our model, we consider data from Planck 2018 and BICEP.

gr-qc

Embedding Warm Natural Inflation in $f(ϕ)T$ gravity

We study warm inflation in the framework of $f(ϕ)T$ gravity, where $ϕ$ is the inflaton and $T$ is the trace of the energy-momentum tensor. The inflaton field is assumed to roll on the natural potential and the result is analyzed in light of Planck 2018 and BICEP/Keck 2021 data. We start our work by obtaining the field equations under slow-roll approximations. We then evaluate the scalar and tensor power spectra and their corresponding spectral index and tensor-to-scalar ratio with a temperature-dependent form of the dissipation coefficient during the inflationary era. We find that the warm inflation model in $f(ϕ)T$ gravity is compatible with observational bands.

gr-qc

Effect of Dissipation on Warm Chromo-Natural Inflation

We examined the chromo-natural inflation in the context of warm inflation with variable dissipation coefficient. The dynamical equations of this model are obtained. We studied the cosmological perturbation theory in this model. The sources of density fluctuations in this model are mainly the thermal fluctuations of the inflaton field like general warm inflationary model. Finally, cosmological observables, namely, the spectral index and tensor to scalar ratio are calculated. It is found that the cosmological observables are consistent with observational data and the tensor to scalar ratio is smaller than that in the chromo-natural inflation.

astro-ph.CO

Warm Inflation in $f(R,T)$ gravity

In this work, we explored warm inflation in the background of $f(R,T)$ gravity in the strong dissipation regime. Considering scalar field for FLRW universe, we derived modified field equations. We then deduced slow-roll parameters under slow-roll approximations followed by power spectrum for scalar and tensor perturbations and their corresponding spectral indices. We have considered Chaotic and Natural potentials and estimated scalar spectral index and tensor-to-scalar ratio for constant as well as variable dissipation factor $Γ$. We found that both the rejected potentials can be revived under the context of $f(R,T)$ gravity with suitable choice of the model parameters. Further, it is seen that within the warm inflationary scenario both the potentials are consistent with Planck 2018 bounds at the Planckian and sub Planckian energy scales.

gr-qc