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We study lithium depletion in low-mass and solar-like stars as a function oftime, using a new diffusion coefficient describing extra-mixing taking place atthe bottom of a convective envelope. This new form is motivated bymulti-dimensional fully compressible, time implicit hydrodynamic simulationsperformed with the MUSIC code. Intermittent convective mixing at the convectiveboundary in a star can be modeled using extreme value theory, a statisticalanalysis frequently used for finance, meteorology, and environmental science.In this letter, we implement this statistical diffusion coefficient in aone-dimensional stellar evolution code, using parameters calibrated frommulti-dimensional hydrodynamic simulations of a young low-mass star. We proposea new scenario that can explain observations of the surface abundance oflithium in the Sun and in clusters covering a wide range of ages, from $\sim$50 Myr to $\sim$ 4 Gyr. Because it relies on our physical model of convectivepenetration, this scenario has a limited number of assumptions. It can explainthe observed trend between rotation and depletion, based on a single additionalassumption, namely that rotation affects the mixing efficiency at theconvective boundary. We suggest the existence of a threshold in stellarrotation rate above which rotation strongly prevents the vertical penetrationof plumes and below which rotation has small effects. In addition to providinga possible explanation for the long standing problem of lithium depletion inpre-main sequence and main sequence stars, the strength of our scenario is thatits basic assumptions can be tested by future hydrodynamic simulations.

Lithium depletion in solar-like stars: effect of overshooting based on realistic multi-dimensional simulations