On the path to obtaining non-linear models for delta Scuti Stars

In this poster, we present two contrasting studies: First, we want to investigate the hypothesis that non-linear
interactions in the power spectra of δ Scuti stars are related to their evolutionary state. For this purpose, we examine a
set of light curves belonging to a sample of young δ Scuti stars observed by the TESS satellite. We expect an absence of
sum combinations in them, and the results agree with such an assumption.
The second study outlines the procedure of numerically solving the non-linear differential equations of oscillations for
High Amplitude Delta Scuti (HADS) stars. The equations are described in terms of the so-called Volterra expansion, and
these coefficients can be estimated observationally through amplitude and phase relations between parents and
children frequencies (see Lares-Martiz et al. 2020). After obtaining these coefficients, the equations can be numerically
solved.