Gevrey smoothing conjecture for the non-cutoff homogeneous Boltzmann equation

Let $0<\nu<1$ be the order of the singular cross section kernel, and let $f$ be a weak solution of the non-cutoff homogeneous Boltzmann equation in $\mathbb{R}^d$ with initial datum in $L^1_2(\mathbb{R}^d)\cap L\log L(\mathbb{R}^d)$, meaning finite mass, energy, and entropy. Gevrey smoothing conjecture. The solution belongs to the Gevrey class $G^{\frac{1}{2\nu}}(\mathbb{R}^d)$ for every strictly positive time. This predicts instantaneous Gevrey regularity for weak solutions with finite mass, energy, and entropy; the paper proves the conjecture for Maxwellian molecules.