CMB and LSS constraints on a single-field model of inflation

A new inflationary scenario whose exponential potential $V(\Phi)$ has a quadratic dependence on the field $\Phi$ in addition to the standard linear term is confronted with the tree-year observations of the Wilkinson-Microwave Anisotropy Probe and the Sloan Digital Sky Survey data. The number of e-folds ($N$), the ratio of tensor-to-scalar perturbations ($r$), the spectral scalar index of the primordial power spectrum ($n_s$) and its running ($dn_s/d\ln k$) depend on the dimensionless parameter $\alpha$ multiplying the quadratic term in the potential. In the limit $\alpha \to 0$ all the results of the standard exponential potential are fully recovered. For values of $\alpha \neq 0$, we find that the model predictions are in good agreement with the current observations of the Cosmic Microwave Background (CMB) anisotropies and Large-Scale Structure (LSS) in the Universe.