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.

In the present work we study the consequences of considering an inflationary universe model in which the Hubble rate has a quasi-exponential dependence in the inflaton field, given by \(H(\phi )=H_{\mathrm{inf}}\exp [\frac{\frac{\phi }{m_\mathrm{p}}}{p\left( 1+\frac{\phi }{m_\mathrm{p}}\right) }]\). We analyze the inflation dynamics under the Hamilton–Jacobi approach, which allows us to consider \(H(\phi )\), rather than \(V(\phi )\), as the fundamental quantity to be specified. By comparing the theoretical predictions of the model together with the allowed contour plots in the \(n_\mathrm{s}-r\) plane and the amplitude of primordial scalar perturbations from the latest Planck data, the parameters charactering this model are constrained. The model predicts values for the tensor-to-scalar ratio r and for the running of the scalar spectral index \(\mathrm{d}n_\mathrm{s}/ \mathrm{d}\ln k\) consistent with the current bounds imposed by Planck, and we conclude that the model is viable.

In the present work we have studied Natural Inflation in the framework of the Randall-Sundrum II brane model (RS-II) in the light of the latest Planck results. Adopting the Randall-Sundrum fine-tuning, the model is characterized by 3 parameters in total, namely the 5-dimensional Planck mass M ₅ and the two mass scales of the inflaton potential f and Λ. We show in the n_s − r plane the theoretical predictions of the model together with the allowed contour plots, and we conclude that the model is viable. By using the Planck results only it is possible to determine the two mass scales of the inflaton potential in terms of M ₅, which remains undetermined. However, there are several good theoretical reasons to consider ahigher-dimensional Planck mass of the order of 10 TeV, which is compatible with primordial nucleosynthesis. If we insist on considering a M ₅ of this order of magnitude all parameters are known.

A warm inflationary Universe in the Randall-Sundrum II model during intermediate inflation is studied. For this purpose, we consider a general form for the dissipative coefficient $\Gamma(T,\phi)=C_{\phi}\,\frac{T^{m}}{\phi^{m-1}}$, and also analyze this inflationary model in the weak and strong dissipative regimes. We study the evolution of the Universe under the slow-roll approximation and find solutions to the full effective Friedmann equation in the brane-world framework. In order to constrain the parameters in our model, we consider the recent data from the BICEP2-Planck 2015 data together with the necessary condition for warm inflation $T>H$, and also the condition from the weak (or strong) dissipative regime.

In the present work we study the consequences of considering an inflationary universe model in which the Hubble rate has a quasi-exponential dependence in the inflaton field, given by $H(\phi)=H_{inf}\exp \left[\frac{\frac{\phi}{m_p}}{p\left(1+\frac{\phi}{m_p}\right)}\right]$. We analyze the inflation dynamics under the Hamilton-Jacobi approach, which allows us to consider $H(\phi)$, rather than $V(\phi)$, as the fundamental quantity to be specified. By comparing the theoretical predictions of the model together with the allowed contour plots in the $n_s-r$ plane and the amplitude of primordial scalar perturbations from the latest Planck data, the parameters charactering this model are constrained. The model predicts values for the tensor-to-scalar ratio $r$ and for the running of the scalar spectral index $dn_s/ d\ln k$ consistent with the current bounds imposed by Planck, and we conclude that the model is viable.