Partial regularity in time for the space-homogeneous Boltzmann equation with very soft potentials

We prove that the set of singular times for weak solutions of the homogeneous Boltzmann equation with very soft potentials constructed as in Villani (1998) has Hausdorff dimension at most $\frac{\mathrm{\mid }\gamma +2s\mathrm{\mid }}{2s}$ with $\gamma \in [-4s,-2s)$ and $s\in (0,1)$.