Abstract
A seminal theorem of Tverberg states that any set of \(T(r,d)=(r-1)(d+1)+1\) points in \({\mathbb {R}}^{d}\) can be partitioned into r subsets whose convex hulls have non-empty r-fold intersection. Almost any collection of fewer points in \({\mathbb {R}}^{d}\) cannot be so divided, and in these cases we ask if the set can nonetheless be P(r, d)-partitioned, i.e., split into r subsets so that there exist r points, one from each resulting convex hull, which form the vertex set of a prescribed convex d-polytope P(r, d). Our main theorem shows that this is the case for any generic \(T(r,2)-2\) points in the plane and any \(r\ge 3\) when \(P(r,2)=P_{r}\) is a regular r-gon, and moreover that \(T(r,2)-2\) is tight. For higher dimensional polytopes and \(r=r_{1}\cdots r_{k}\), \(r_{i} \ge 3\), this generalizes to \(T(r,2k)-2k\) generic points in \({\mathbb {R}}^{2k}\) and orthogonal products \(P(r,2k)=P_{r_{1}}\times \cdots \times P_{r_{k}}\) of regular polygons, and likewise to \(T(2r,2k+1)-(2k+1)\) points in \({\mathbb {R}}^{2k+1}\) and the product polytopes \(P(2r,2k+1)=P_{r_{1}}\times \cdots \times P_{r_{k}}\times P_{2}\). As with Tverberg’s original theorem, our results admit topological generalizations when r is a prime power, and, using the “constraint method” of Blagojević, Frick, and Ziegler, allow for dimensionally restricted versions of a van Kampen–Flores type and colored analogues in the fashion of Soberón.
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References
Asada, M., Chen, R., Frick, F., Huang, F., Polevy, M., Stoner, D., Tsang, L.H., Wellner, Z.: On Reay’s relaxed Tverberg conjecture and generalizations of Conway’s thrackle conjecture. Electron. J. Combin. 25(3), # 3.16 (2018)
Bárány, I.: A generalization of Carathéodory’s theorem. Discrete Math. 40(2–3), 141–152 (1982)
Bárány, I., Larman, D.G.: A colored version of Tverberg’s theorem. J. Lond. Math. Soc. 45(2), 314–320 (1992)
Bárány, I., Shlosman, S.B., Szűcs, A.: On a topological generalization of a theorem of Tverberg. J. Lond. Math. Soc. 23(1), 158–164 (1981)
Bárány, I., Soberón, P.: Tverberg’s theorem is 50 years old: a survey. Bull. Am. Math. Soc. 55(4), 459–492 (2018)
Blagojević, P.V.M., Frick, F., Ziegler, G.M.: Tverberg plus constraints. Bull. Lond. Math. Soc. 46(5), 953–967 (2014)
Blagojević, P.V.M., Frick, F., Ziegler, G.M.: Barycenters of polytope skeleta and counterexamples to the topological Tverberg conjecture, via constraints. J. Eur. Math. Soc. 21(7), 2107–2116 (2019)
Blagojević, P.V.M., Matschke, B., Ziegler, G.M.: Optimal bounds for the colored Tverberg problem. J. Eur. Math. Soc. 17(4), 739–754 (2015)
Blagojević, P.V.M., Ziegler, G.M.: Beyond the Borsuk–Ulam theorem: the topological Tverberg story. In: A Journey Through Discrete Mathematics, pp. 273–341. Springer, Cham (2017)
De Loera, J.A., Goaoc, X., Meunier, F., Mustafa, N.H.: The discrete yet ubiquitous theorems of Carathéodory, Helly, Sperner, Tucker, and Tverberg. Bull. Am. Math. Soc. 56(3), 415–511 (2019)
Flores, A.: Über \(n\)-dimensionale Komplexe, die im \(R_{2n+1}\) absolut selbstverschlungen sind. Erg. Math. Kolloqu. 6, 4–7 (1935)
Frick, F.: Counterexamples to the topological Tverberg conjecture. Oberwolfach Rep. 11(1), 34–37 (2014)
Gromov, M.: Singularities, expanders and topology of maps. Part 2: from combinatorics to topology via algebraic isoperimetry. Geom. Funct. Anal. 20(2), 416–526 (2010)
van Kampen, E.R.: Komplexe in euklidischen Räumen. Abh. Math. Sem. Univ. Hamburg 9(1), 72–78 (1933)
Mabillard, I., Wagner, U.: Eliminating Tverberg points, I. An analogue of the Whitney trick. In: 30th Annual Symposium on Computational Geometry (Kyoto 2014), pp. 171–180. ACM, New York (2014)
Matschke, B.: A survey on the square peg problem. Not. Am. Math. Soc. 61(4), 346–352 (2014)
Meyerson, M.D.: Balancing acts. Topol. Proc. 6(1), 59–75 (1981)
Nielsen, M.J.: Triangles inscribed in simple closed curves. Geom. Dedicata 43(3), 291–297 (1992)
Özaydin, M.: Equivariant maps for the symmetric group (1987). http://digital.library.wisc.edu/1793/63829
Perles, M.A., Sigron, M.: Some variations on Tverberg’s theorem. Isr. J. Math. 216(2), 957–972 (2016)
Reay, J.R.: Several generalizations of Tverberg’s theorem. Isr. J. Math. 34(3), 238–244 (1979)
Sarkaria, K.S.: A generalized van Kampen–Flores theorem. Proc. Am. Math. Soc. 111(2), 559–565 (1991)
Sarkaria, K.S.: Tverberg partitions and Borsuk–Ulam theorems. Pac. J. Math. 196(1), 231–241 (2000)
Serre, J.-P.: Linear Representations of Finite Groups. Graduate Texts in Mathematics, vol. 42. Springer, New York (1977)
Simon, S.: Average-value Tverberg partitions via finite Fourier analysis. Isr. J. Math. 216(2), 891–904 (2016)
Soberón, P.: Equal coefficients and tolerance in coloured Tverberg partitions. Combinatorica 35(2), 235–252 (2015)
Toeplitz, O.: Ueber einige Aufgaben der Analysis situs. Verhandlungen der Schweizerischen Naturforschenden Gesellschaft in Solothurn 4, 197 (1911)
Tverberg, H.: A generalization of Radon’s theorem. J. Lond. Math. Soc. 41, 123–128 (1966)
Volovikov, A.Yu.: On a topological generalization of the Tverberg theorem. Math. Notes 59(3), 324–326 (1996)
Volovikov, A.Yu.: On the van Kampen–Flores theorem. Math. Notes 59(5), 477–481 (1996)
Živaljević, R.T., Vrećica, S.T.: The colored Tverberg’s problem and complexes of injective functions. J. Comb. Theory Ser. A 61(2), 309–318 (1992)
Acknowledgements
The authors thank the anonymous referee for many useful comments which improved the clarity and exposition of the manuscript, as well as for alerting the authors to connections with the square peg problem. The authors likewise thank Florian Frick and Pablo Soberón for helpful discussions and suggestions.
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Leiner, L., Simon, S. Regular Polygonal Partitions of a Tverberg Type. Discrete Comput Geom 66, 1053–1071 (2021). https://doi.org/10.1007/s00454-021-00288-2
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DOI: https://doi.org/10.1007/s00454-021-00288-2