Kusner's Klein-bottle conjecture

Prove that the Klein bottle in \(\mathbb{S}^3\) with least possible Willmore energy is the Lawson Klein bottle \(\tau_{1,2}\).

Background

The paper reduces Kusner’s conjecture for Klein bottles containing and symmetric about the great circle to the corresponding Möbius-band characterization problems. The conjecture concerns the global Willmore minimizer among immersed Klein bottles in the round three-sphere.

References

The Klein bottle in $\mathbb{S}3$ of least possible Willmore energy is the Lawson Klein bottle $\tau_{1,2}$.

— On the Willmore energy of Möbius bands  (2609.26745 - Bernstein et al., 22 Sep 2026) in Conjecture 1.5 (Introduction)