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SIAM Journal on Discrete Mathematics· 2026Q1

On the Number of Pairwise Touching Cylinders in \({\mathbb{R}}\)\(^{{d}}\)

Jozsef Solymosi, Joshua Zahl

Short summary

Researchers established exponential upper bounds on the number of mutually touching unit cylinders in d-dimensional space (R^d).

AI-generated from the title and abstract; the full text is not read.

Key points

  • Derived exponential upper bounds on mutually touching unit cylinders in R^d.
  • The method uses polynomial equalities and inequalities to model cylinder touching.
  • Extends previous work which showed 7 cylinders can mutually touch in R^3.

AI-generated from the title and abstract; the full text is not read.

Abstract

Abstract. John E. Littlewood posed the question “Is it possible in 3- space for seven infinite circular cylinders of unit radius each to touch all the others? Seven is the number suggested by counting constants.” Bozóki, Lee, and Rónyai constructed a configuration of 7 mutually touching unit cylinders. The best-known upper bounds show that at most 10 unit cylinders in [Formula: see text] can mutually touch. We consider this problem in higher dimensions, and obtain exponential (in [Formula: see text]) upper bounds on the number of mutually touching cylinders in [Formula: see text]. Our method is fairly flexible, and it makes use of the fact that cylinder touching can be expressed as a combination of polynomial equalities and nonequalities.

The authors' abstract, as published at the source. SIAM Journal on Discrete Mathematics, 2026 · DOI ↗

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Field: Computer Graphics and Computer-Aided Design

Computer Graphics and Computer-Aided DesignComputer Science