We show that the hexagonal honeycomb is optimal among convex periodic tessellations of the plane, provided the cost functional is lower semicontinuous with respect to the Hausdorff convergence, and decreasing under Steiner symmetrization.

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  1. A. Baernstein: Symmetrization in Analysis, New Mathematical Monographs Vol. 36, Cambridge University Press, Cambridge (2019).https://doi.org/10.1017/9781139020244Google Scholar
  2. B. Bogosel, D. Bucur, I. Fragalà: The nonlocal isoperimetric problem for polygons: Hardy-Littlewood and Riesz inequalities, Math. Ann. 389/2 (2023) 1835–1882.https://doi.org/10.1007/s00208-023-02683-xGoogle Scholar
  3. M. Bonacini, R. Cristoferi, I. Topaloglu: Riesz-type inequalities and overdetermined problems for triangles and quadrilaterals, J. Geom. Analysis 32/2 (2022), art.no. 48.https://doi.org/10.1007/s12220-021-00737-7Google Scholar
  4. D. Bucur, I. Fragalà: Proof of the honeycomb asymptotics for optimal Cheeger clusters, Adv. Math. 350 (2019) 97–129.https://doi.org/10.1016/j.aim.2019.04.036Google Scholar
  5. D. Bucur, I. Fragalà: On the honeycomb conjecture for Robin Laplacian eigenvalues, Commun. Contemp. Math. 21/2 (2019), art.no. 185007, 29p.https://doi.org/10.1142/S0219199718500074Google Scholar
  6. D. Bucur, I. Fragalà, B. Velichkov, G. Verzini: On the honeycomb conjecture for a class of minimal convex partitions, Trans. Amer. Math. Soc. 370/10 (2018) 7149–7179.https://doi.org/10.1090/tran/7326Google Scholar
  7. L. A. Caffarelli, F. H. Lin: An optimal partition problem for eigenvalues, J. Sci. Comput. 31/1-2 (2007) 5–18.https://doi.org/10.1007/s10915-006-9114-8Google Scholar
  8. A. Cesaroni, I. Fragalà, M. Novaga: Lattice tilings minimizing nonlocal perimeters, Commun. Contemp. Math. 27/6 (2025), art.no. 2450043.https://doi.org/10.1142/S0219199724500433Google Scholar
  9. A. Cesaroni, M. Novaga: Periodic partitions with minimal perimeter, Nonlinear Analysis 243 (2024), art.no. 113522, 16p.https://doi.org/10.1016/j.na.2024.113522Google Scholar
  10. E. S. Fedorov: The symmetry of regular systems of figures, Proceedings of the Imperial St. Petersburg Mineralogical Society 28 (1891) 1–146.Google Scholar
  11. P. Gallagher, W. Ghang, D. Hu, Z. Martin, M. Miller, B. Perpetua, S. Waruhiu: Surface-area-minimizing n-hedral tiles, Rose-Hulman Undergraduate Math. J. 15/1 (2014), art.no. 13.Google Scholar
  12. K. Glasner: Segregation and domain formation in non-local multi-species aggregation equations, Phys. D 456 (2023), art.no. 133936, 11p.https://doi.org/10.1016/j.physd.2023.133936Google Scholar
  13. T. C. Hales: The honeycomb conjecture, Discrete Comput. Geom. 25/1 (2001) 1–22.https://doi.org/10.1007/s004540010071Google Scholar
  14. A. Henrot: Extremum Problems for Eigenvalues of Elliptic Operators, Frontiers in Mathematics, Birkhäuser Verlag, Basel (2006).https://doi.org/10.1007/3-7643-7706-2Google Scholar
  15. E. H. Lieb, M. Loss: Analysis, 2nd ed., Graduate Studies in Mathematics Vol. 14, American Mathematical Society, Providence (2001).https://doi.org/10.1090/gsm/014Google Scholar
  16. F. Maggi: Sets of Finite Perimeter and Geometric Variational Problems, Cambridge Studies in Advanced Mathematics Vol. 135, Cambridge University Press, Cambridge (2012).https://doi.org/10.1017/CBO9781139108133Google Scholar
  17. P. McMullen: Convex bodies which tile space by translation, Mathematika 27/1 (1980) 113–121.https://doi.org/10.1112/S0025579300010007Google Scholar
  18. F. Morgan: The hexagonal honeycomb conjecture, Trans. Amer. Math. Soc. 351/5 (1999) 1753–1763.https://doi.org/10.1090/S0002-9947-99-02356-9Google Scholar
  19. W. Thomson (Lord Kelvin): On the division of space with minimum partitional area, Acta Math. 11/1-4 (1887) 121–134.https://doi.org/10.1007/BF02612322Google Scholar
  20. D. Weaire (ed.): The Kelvin Problem. Foam Structures of Minimal Surface Area, Taylor & Francis, London (1997).Google Scholar

A. Cesaroni, I. Fragalà, M. Novaga. “A Note on the Honeycomb Optimality among Periodic Convex Tilings.” Journal of Convex Analysis 33 (2026), No. 1&2, 421–428. https://doi.org/10.68381/jca33026