Check out the video of the talk: (slides below)
Check out Mariel’s slides:
Non-linear terms in Delta Scuti stars power spectra
Non-linear theory of pulsations could explain special characteristics observed in many variable star light curves, however, non-linear models are far from being complete. Ultra-precise photometric data captures the footprints of non-linear processes happening within a pulsating star, which are translated in their power spectra as combination frequencies (additions and subtraction of the eigenfrequencies). In this talk, I will present a study of combination frequencies in δ Scuti star power spectra, aiming to empirically characterize their non-linear behavior. Based on the study of frequency, amplitude and phase relations given by the Volterra series formulation (a general non-linear model), a self-consistent method to identify combination frequencies with high precision, a possible method to unambiguously identify the non-linear process behind a combination frequency, as well as the possible first use of combination frequencies for mode identification in δ Sct stars are, among others, the most relevant results.