Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-22T20:57:22.075Z Has data issue: false hasContentIssue false

Uniqueness of Certain Spherical Codes

Published online by Cambridge University Press:  20 November 2018

Eiichi Bannai
Affiliation:
Ohio State University, Columbus, Ohio
N. J. A. Sloane
Affiliation:
Bell Laboratories, Murray Hill, New Jersey
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In this paper we show that there is essentially only one way of arranging 240 (resp. 196560) nonoverlapping unit spheres in R8 (resp. R24) so that they all touch another unit sphere, and only one way of arranging 56 (resp. 4600) spheres in R8 (resp. R24) so that they all touch two further, touching spheres. The following tight spherical t-designs are unique: the 5-design in Ω7, the 7-designs in Ω8 and Ω23, and the 11-design in Ω24. It was shown in [20] that the maximum number of nonoverlapping unit spheres in R8 (resp. R24) that can touch another unit sphere is 240 (resp. 196560). Arrangements of spheres meeting these bounds can be obtained from the E8 and Leech lattices, respectively. The present paper shows that these are the only arrangements meeting these bounds.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1981

References

1. Abramowitz, M. and Stegun, I. A., Handbook of mathematical functions, National Bureau of Standards Applied Math. Series 55 (Washington, DC, U.S. Dept. of Commerce, 1972).Google Scholar
2. Bannai, E. and Damerell, R. M., Tight spherical designs, I, J. Math. Soc. Japan 31 (1979), 199207.Google Scholar
3. Bannai, E. and Damerell, R. M., Tight spherical designs, II, J. London Math. Soc. 21 (1980), 1330.Google Scholar
4. Bourbaki, N., Groupes et algebras de Lie, Chapitres IV, V, VI, Actualités Scientif. et Indust. 1887 (Hermann, Paris, 1968).Google Scholar
5. Conway, J. H., A characterization of Leech's lattice, Inventiones Math. 7 (1969), 137142.Google Scholar
6. Curtis, R. T., A new combinatorial approach to M24, Math. Proc. Camb. Phil. Soc. 79 (1976), 2541.Google Scholar
7. Delsarte, P., An algebraic approach to the association schemes of coding theory, Philips Research Reports Supplements 10 (1973).Google Scholar
8. Delsarte, P. and Goethals, J.-M., Unrestricted codes with the Golay parameters are unique, Discrete Math. 12 (1975), 211224.Google Scholar
9. Delsarte, P., Goethals, J.-M. and Seidel, J. J., Spherical codes and designs, Geometriae Dedicata 6 (1977), 363388.Google Scholar
10. Goethals, J. M. and Seidel, J. J., Spherical designs, in Relations between combinatorics and other parts of mathematics, Proc. Symp. Pure Math. 34 (Amer. Math. Soc, Providence, Rhode Island, 1979), 255272.Google Scholar
11. Jônsson, W., On the Mathieu groups M22, M23, M24 and the uniqueness of the associated Steiner systems, Math. Zeit. 125 (1972), 193214.Google Scholar
12. Kabatiansky, G. A. and Levenshtein, V. I., Bounds for packings on a sphere and in space, Problems of Information Transmission 14, No 1 (1978), 117.Google Scholar
13. Kneser, M., Klassenzahlen definiter quadratischer Formen, Archiv der Math. 8 (1957), 241250.Google Scholar
14. Leech, J., Notes on sphere packings, Can. J. Math. 19 (1967), 251267.Google Scholar
15. Leech, J. and Sloane, N. J. A., Sphere packing and error-correcting codes, Can. J. Math. 23 (1971), 718745.Google Scholar
16. Lloyd, S. P., Hamming association schemes and codes on spheres, SIAM J. of Math. Analysis 11 (1980), 488505.Google Scholar
17. Liineburg, H., Transitive Erweiterungen endlicher Permutations gruppen, Lecture Notes in Math. 84 (Springer-Verlag, New York, 1969).Google Scholar
18. MacWilliams, F. J. and Sloane, N. J. A., The theory of error-correcting codes (North-Holland, Amsterdam, and Elsevier/North-Holland, New York, 1977).Google Scholar
19. Niemeier, H.-V., Definite quadratische Formen der Dimension 24 und Diskriminante 1, J. Number Theory 5 (1973), 142178.Google Scholar
20. Odlyzko, A. M. and Sloane, N. J. A., New bounds on the number of unit spheres that can touch a unit sphere in n dimensions, J. Combinatorial Theory 26A (1979), 210214.Google Scholar
21. Pless, V., On the uniqueness of the Golay codes, J. Combinatorial Theory 5 (1968), 215228.Google Scholar
22. Pless, V. and Sloane, N. J. A., On the classification and enumeration of self-dual codes, J. Combinatorial Theory 18A (1975), 313335.Google Scholar
23. Simonnard, M., Linear programming (Prentice-Hall, Englewood Cliffs, NJ, 1966).Google Scholar
24. Sloane, N. J. A., An introduction to association schemes and coding theory in Theory and application of special functions (Academic Press, New York, 1975), 225260.Google Scholar
25. Sloane, N. J. A., Binary codes, lattices and sphere-packings in Combinatorial surveys Proc. 6th British Combinatorics Conf. (Academic Press, London and New York, 1977), 117164.Google Scholar
26. Sloane, N. J. A., Self-dual codes and lattices, in Relations between combinatorics and other parts of mathematics, Proc. Symp. Pure Math. 34 (Amer. Math. Soc, Providence, Rhode Island, 1979), 273308.Google Scholar
27. Stanton, R. G., The Mathieu groups, Can. J. Math. 3 (1951), 164174.Google Scholar
28. Witt, E., Uber Steinersche Système, Abh. Math. Sem. Hamburg 12 (1938), 265275 Google Scholar