Subcritical pitchfork conjecture for the Ren–Wei branch

Let $\chi$ be the fissility parameter and let $\chi_*$ be the bifurcation value. The Ren–Wei branch is the equilibrium branch emerging at this bifurcation. Subcritical pitchfork conjecture. The bifurcation at $\chi=\chi_*$ is of subcritical pitchfork type. The equilibrium on the Ren–Wei branch exists only for $\chi<\chi_*$ and is unstable. This conjecture is proposed in opposition to the supercritical scenario, based on the paper's numerical results; the supplied text gives no rigorous resolution.