  The power of asteroseismology relies on the ability to infer the stellar
structure from the unambiguous frequency identification of the corresponding
pulsation mode. Hence, the use of a Fourier transform is in the basis of
asteroseismic studies. Nevertheless, the difficulties with the interpretation
of the frequencies found in many stars lead us to reconsider whether Fourier
analysis is the most appropriate technique to identify pulsation modes. We have
found that the data, usually analyzed using Fourier techniques, present a
non-analyticity originating from the lack of connectivity of the underlying
function describing the physical phenomena. Therefore, the conditions for the
Fourier series to converge are not fulfilled. In the light of these results, we
examine in this talk some stellar light curves from different asteroseismology
space missions (CoRoT, Kepler and SoHO) in which the interpretation of the data
in terms of Fourier frequencies becomes difficult. We emphasize the necessity
of a new interpretation of the stellar light curves in order to identify the
correct frequencies of the pulsation modes.
