Abstract

The secular evolution of protoplanetary discs is deeply intertwined with both planet formation and accretion of the central protostar. Planetesimals, the building blocks of planets, form and evolve from dust grains within the disc – which follow the dynamics of the gaseous or solid component, depending on their relative size; on the other hand, the protostar is fed by the disc itself, through the accretion of material that loses angular momentum and drifts inwards. The physical mechanism driving accretion is still widely debated. The standard paradigm of viscous evolution prescribes a macroscopic, turbulent viscosity as cause of a redistribution of angular momentum within the disc; however, the observational evidence of low levels of turbulence is challenging this scenario. Magnetohydrodynamic winds, on the other hand, prescribe material – and angular momentum with it – to be removed from the disc surface. Determining the relative contribution of the viscous and wind-driven paradigms is a compelling issue, mostly addressed looking at their impact on the observables of disc populations. In this talk, I show how the accretion model impacts the time evolution of (i) the disc properties-stellar mass correlations and (ii) the distribution of disc lifetimes. With a combination of disc population synthesis and analytical calculations, I show that both observables trace the underlying accretion mechanism: convolving the synthetic populations with the uncertainties, I assess the observability of the model-dependent features and conclude that, to use them as evolutionary proxies, we need (i) larger samples and (ii) more accurate disc mass determinations.