Belfiore–Solé secrecy function conjecture for formally unimodular lattices

Let $\Lambda$ be a formally unimodular lattice, and let $\Xi_{\Lambda}(\tau)$ denote its secrecy function and $\xi_{\Lambda}$ its maximum value. Belfiore–Solé secrecy function conjecture. The secrecy function achieves its maximum at $\tau=1$, i.e.,

$$\xi_{\Lambda}=\Xi_{\Lambda}(1).$$

This conjecture concerns the weak secrecy symmetry point of formally unimodular lattices and is the lattice version of the secrecy gain conjecture introduced by Belfiore and Solé.