Energetical aspects of solar-like oscillations in red giants

CoRoT and Kepler observations of red giants reveal very rich spectra of non-radial solar- like oscillations allowing us to probe their internal structure.
The study of energetic aspects of these oscillations is of great importance to predict the peak parameters in the power spectrum.
The theoretical determination of lifetimes (or equivalently width) of the modes require non- adiabatic computations. Next, combined with a stochastic excitation model, we can also predict the height of the mode and finally obtain theoretical power spectra.
Comparison between our theoretical predictions with observations give important constraint on red-giants models.
Lifetimes and amplitudes of modes trapped in the envelope (e.g. radial modes) constrain the characteristics of the convective envelope and its time-dependent interaction with oscillations.
Lifetimes of mixed-modes (mainly dipolar modes) strongly depend on mode trapping, allowing us to probe the core of red-giants.
I will discuss under which circumstances mixed modes are detectable for a large variety of red-giant stellar models, with emphasis on the effect of the evolutionary status of the star (along the red-giant branch and during the He-burning phase) for a wide range of stellar masses (from 0.7 to 4 Msun ) on theoretical power spectra.