Abstract
We study combinatorics of billiard partitions which arose recently in the description of periodic trajectories of ellipsoidal billiards in d-dimensional Euclidean and pseudo-Euclidean spaces. Such partitions uniquely codify the sets of caustics, up to their types, which generate periodic trajectories. The period of a periodic trajectory is the largest part while the winding numbers are the remaining summands of the corresponding partition. In order to take into account the types of caustics as well, we introduce weighted partitions and provide closed forms for the generating functions of these partitions.
Similar content being viewed by others
References
Adabrah, A.K., Dragović, V., Radnović, M.: Periodic billiards within conics in the Minkowski plane and Akhiezer polynomials. Regulat. Chaotic Dyn. 24(5), 464–501 (2019). https://doi.org/10.1134/S1560354719050034
Ahiezer, N.I.: Lekcii po Teorii Approksimacii. OGIZ, Moscow-Leningrad (1947)
Andrews, G.E.: The Theory of Partitions. Addison-Weslay, Readings (1976)
Audin, M.: Courbes algébriques et systèmes intégrables: géodesiques des quadriques. Expo. Math. 12, 193–226 (1994)
Casas, P.S., Ramírez-Ros, R.: The frequency map for billiards inside ellipsoids. SIAM J. Appl. Dyn. Syst. 10(1), 278–324 (2011)
Casas, P.S., Ramírez-Ros, R.: Classification of symmetric periodic trajectories in ellipsoidal billiards. Chaos 22, 2, 026110, 24 (2012)
Dragović, V., Radnović, M.: Poncelet Porisms and Beyond. Springer, irkhauser (2011)
Dragović, V., Radnović, M.: Ellipsoidal billiards in pseudo-Euclidean spaces and relativistic quadrics. Adv. Math. 231, 1173–1201 (2012)
Dragović, V., Radnović, M.: Periodic ellipsoidal billiard trajectories and extremal polynomials. Commun. Math. Phys. 372(1), 183–211 (2019). https://doi.org/10.1007/s00220-019-03552-y
Dragović, V., Radnović, M.: Caustics of Poncelet polygons and classical extremal polynomials. Regul. Chaotic Dyn. 24(1), 1–35 (2019)
Dragović, V., Radnović, M.: Periodic trajectories of ellipsoidal billiards in the 3-dimensional Minkowski space, Asymptotic, Algebraic and Geometric Aspects of Integrable Systems, Springer Proceedings in Mathematics and Statistics (PROMS) Series (2020)
Kreĭn, M.G., Levin, B.Ya., Nudel’ man, A. A.: On special representations of polynomials that are positive on a system of closed intervals, and some applications, Translated from the Russian by Lev J. Leifman and Tatyana L. Leifman, Functional analysis, optimization, and mathematical economics, Oxford University Press, New York, 56–114 (1990)
Peherstorfer, F., Schiefermayr, K.: Description of extremal polynomials on several intervals and their computation I, II. Acta Math. Hungary 83, 1-2, 27–58, 59–83 (1999)
Ramírez-Ros, R.: On Cayley conditions for billiards inside ellipsoids. Nonlinearity 27(5), 1003–1028 (2014)
Acknowledgements
The authors are grateful to the referee for suggestions that improved the presentation.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
In honor of Richard Askey, a great man and a great mathematician
GEA was partially supported by Simons Foundation Grant #633284. The research of VD and MR was supported by the Discovery Project #DP190101838 Billiards within confocal quadrics and beyond from the Australian Research Council, the Serbian Ministry of Education, Technological Development and Science and the Science Fund of Serbia. VD would like to thank the University of Sydney Mathematical Research Institute and their International Visitor Program for kind hospitality.
Rights and permissions
About this article
Cite this article
Andrews, G.E., Dragović, V. & Radnović, M. Combinatorics of periodic ellipsoidal billiards. Ramanujan J 61, 135–147 (2023). https://doi.org/10.1007/s11139-020-00346-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11139-020-00346-y
Keywords
- Euclidean billiard partitions
- Space-type partitions
- Time-type partitions
- Light-type partitions
- Irreducible partitions
- Weighted Euclidean billiard partitions
- Generating functions