Branching processes and neutron transport equations represent two interconnected yet distinct areas that lie at the interface of probability theory, statistical physics and applied mathematics.

Let n ≥ 3. We show that there is no topological vector space $\mathrm{X}\subset {\mathrm{L}}^{\mathrm{\infty }}\cap {\mathrm{L}}_{\mathrm{l}\mathrm{o}\mathrm{c}}^{1 ...