Are observed mixed modes able to slow-down the core of red-giants?
Kevin Belkacem (Paris Observatory), J.P. Marques (Institut d)

The detection of mixed modes in subgiants and red giants by the CoRoT and Kepler space-borne missions allowed us to investigate for the first time the internal structure of evolved low-mass stars. These results indicate that the mean core rotation rate was much lower than expected, and that it slowed down with age as the star climbs the RGB. Although a number of physical processes have been proposed, no clear answer emerged. The quest for a mechanism efficient enough to transport the required angular momentum from the core of red giants is still ongoing. In this talk, we will consider the ability and efficiency of the observed mixed modes to slow-down the core of red giants.