Didid's zone-width and inradius conjecture

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Let F4D0Z1,…,Zn⊂Sd−1F4D0\mathbf{Z}_1,\dots,\mathbf{Z}_n\subset \mathbb{S}^{d-1}, with d>2d>2, be zones of widths 2β1,…,2βn2\beta_1,\dots,2\beta_n, respectively. Suppose that

Sd−1∖(⋃i=1nZi)\mathbb{S}^{d-1}\setminus\left(\bigcup_{i=1}^n\mathbf{Z}_i\right)

consists of 2m2m spherically convex open connected components with inradii F4D0γ1,…,γ2mF4D0\gamma_1,\dots,\gamma_{2m}, respectively. Didid's conjecture. Then

2β1+⋯+2βn+γ1+⋯+γ2m≥π.2\beta_1+\dots+2\beta_n+\gamma_1+\dots+\gamma_{2m}\geq\pi.

This is a generalization of the zone-covering theorem: it relates the total widths of the zones and the inradii of the complementary components. The supplied text attributes the problem to Didid through Polyanskii's account, but gives no resolution.

References

Primary source

Károly Bezdek and Zsolt Lángi, “On separability in discrete geometry”, arXiv:2407.20169 (2025).

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