Unification of polynomial and exponential cosmological attractors in inflation

A new cosmological model has successfully unified two types of inflationary attractors, exponential and polynomial, within a single formulation. This advance allows interpolation between both behaviors through a continuous parameter, offering a more flexible tool to describe the early cosmic inflation phase. The unification is based on a family of $\alpha$-attractor models, which are known for their robustness and for predicting values of the spectral index $n_s$ and the tensor-to-scalar ratio $r$ compatible with cosmic microwave background (CMB) observations. Traditionally, inflationary models have been classified into distinct categories according to the shape of their scalar potential, leading to different predictions for cosmological observables. Exponential and polynomial attractors represent two important classes that have been studied separately. The ability to transition between them with a single parameter $\mu$ simplifies the theoretical framework and allows for the exploration of a wider range of inflationary scenarios in a coherent manner. The study demonstrates that, by varying this interpolation parameter $\mu$, the model can generate a wide range of values for the spectral index $n_s$. This is crucial, as it allows the model's predictions to be adjusted to match current and future observations of the cosmic microwave background radiation and data from large galaxy surveys, such as those provided by the Dark Energy Spectroscopic Instrument (DESI). This flexibility is fundamental for the confrontation between inflationary theory and precision cosmological data.