Finite measure for the initial conditions of inflation

Inflation sets out to solve several problems (horizon, flatness, homogeneity) at once in order to avoid extreme fine-tuning in Hot Big Bang cosmology, but the question of possible fine-tuning of the initial conditions to achieve sufficient inflation counteracts this feature. The authors present a refreshing new idea to quantify this fine-tuning, that avoids regularization ambiguities of previous approaches and shows that it depends on the value of the cosmological constant in the past.