Finiteness and strict growth conjecture for compact packings with n radii

About 9 years old · traced to

For each n∈Nn\in\mathbb{N}, let Πn\Pi_n denote the set of compact packings of the plane with nn distinct circle radii, represented by radius ratios (rn−1,rn−2,…,r1)(r_{n-1},r_{n-2},\ldots,r_1). The construction obtained by filling interstitial gaps of a compact (n−1)(n-1)-packing corresponds to the truncation (rn−2,…,r1)∈Πn−1(r_{n-2},\ldots,r_1)\in\Pi_{n-1}. Finiteness and strict growth conjecture. For every n∈Nn\in\mathbb{N}, the set Πn\Pi_n is finite and the sequence (∣Πn∣)n∈N(|\Pi_n|)_{n\in\mathbb{N}} is strictly increasing. Furthermore, for every n∈Nn\in\mathbb{N}, there exists an element (rn−1,rn−2,…,r1)∈Πn(r_{n-1},r_{n-2},\ldots,r_1)\in\Pi_n with (rn−2,…,r1)∉Πn−1(r_{n-2},\ldots,r_1)\notin\Pi_{n-1}; equivalently, not every compact nn-packing arises from filling interstitial gaps of a compact (n−1)(n-1)-packing. The conjecture extends the observed finiteness of Π2\Pi_2 and Π3\Pi_3 and predicts genuinely new compact packings at every number of radii, rather than only those obtained by recursively filling gaps.

References

Primary source

Miek Messerschmidt, “On compact packings of the plane with circles of three radii”, arXiv:1709.03487 (2019).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.