  With the rapid development of asteroseismology thanks to space-based
photometry missions such as CoRoT, Kepler, TESS, and in the future, PLATO, and
the use of inversion techniques, quasi-model-independent constraints on the
stellar properties can be extracted from a given stellar oscillation spectrum.
In this context, inversions based on frequency separation ratios, that are less
sensitive to surface effects, appear as a promising technique to constrain the
properties of stellar convective cores. We developed an inversion based on
frequency separation ratios with the goal of damping the surface effects of the
oscillation frequencies. Using this new inversion, we defined a new indicator
to constrain the boundary mixing properties of convective cores in solar-like
oscillators. We verified our inversion technique by conducting tests in a
controlled environment, where the stellar mass and radius are known exactly,
and conducted an extensive hare and hounds exercise. The inversion is not
affected by surface effects. With the construction of an extensive set of
models, favoured and forbidden regions can be highlighted in the parameter
space. If the ratios are well fitted, the inversion is unsurprisingly not
providing additional information. The indicator coupled with the inversion
based on frequency separation ratios seems promising at probing the properties
of convective cores, especially for F-type stars exhibiting solar-like
oscillations.
