Abstract
We classify semidiscrete equations of hyperbolic type. We study the class of equations of the form
where the unknown function \(u_n(x)\) depends on one discrete (\(n\)) and one continuous (\(x\)) variables. The classification is based on the requirement that generalized symmetries exist in the discrete and continuous directions. We consider the case where the symmetries are of order \(3\) in both directions. As a result, a list of equations with the required conditions is obtained.
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Notes
The terminology belongs to F. Calogero.
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Acknowledgments
The author is grateful to the anonymous referee for the critical comments and a valuable advice.
Funding
This research was supported by the Russian Science Foundation (grant No. 21-11-00006), https://rscf.ru/en/project/21-11-00006/.
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Translated from Teoreticheskaya i Matematicheskaya Fizika, 2023, Vol. 217, pp. 404–415 https://doi.org/10.4213/tmf10512.
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Garifullin, R.N. Classification of semidiscrete equations of hyperbolic type. The case of third-order symmetries. Theor Math Phys 217, 1767–1776 (2023). https://doi.org/10.1134/S0040577923110119
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DOI: https://doi.org/10.1134/S0040577923110119