One-dimensional inelastic Boltzmann equation: Stability and uniqueness of self-similar $L^1$-profiles for moderately hard potentials

We prove the stability of $L^1$ self-similar profiles under the hard-to-Maxwell potential limit for the one-dimensional inelastic Boltzmann equation with moderately hard potentials which, in turn, leads to the uniqueness of such profiles for hard potentials collision kernels of the form $\mathrm{\mid }\cdot {\mathrm{\mid }}^{\gamma }$ with $\gamma >0$ sufficiently small (explicitly quantified). Our result provides the first uniqueness statement for self-similar profiles of inelastic Boltzmann models allowing for strong inelasticity besides the explicitly solvable case of Maxwell interactions (corresponding to $\gamma =0$). Our approach relies on a perturbation argument from the corresponding Maxwell model and a careful study of the associated linearized operator recently derived in the companion paper \cite{maxwel}. The results can be seen as a first step towards a complete proof, in the one-dimensional setting, of a conjecture in \cite{ernst} regarding the determination of the long-time behaviour of solutions to inelastic Boltzmann equation, at least, in a regime of moderately hard potentials.