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New results on integrability of the Kahan-Hirota-Kimura discretizations

Mathematical Physics 2019-11-11 v1 math.MP Numerical Analysis Exactly Solvable and Integrable Systems

Abstract

R. Hirota and K. Kimura discovered integrable discretizations of the Euler and the Lagrange tops, given by birational maps. Their method is a specialization to the integrable context of a general discretization scheme introduced by W. Kahan and applicable to any vector field with a quadratic dependence on phase variables. We report several novel observations regarding integrability of the Kahan-Hirota-Kimura discretization. For several of the most complicated cases for which integrability is known (Clebsch system, Kirchhoff system, and Lagrange top), - we give nice compact formulas for some of the more complicated integrals of motion and for the density of the invariant measure, and - we establish the existence of higher order Wronskian Hirota-Kimura bases, generating the full set of integrals of motion. While the first set of results admits nice algebraic proofs, the second one relies on computer algebra.

Keywords

Cite

@article{arxiv.1805.12490,
  title  = {New results on integrability of the Kahan-Hirota-Kimura discretizations},
  author = {Matteo Petrera and Yuri B. Suris},
  journal= {arXiv preprint arXiv:1805.12490},
  year   = {2019}
}

Comments

28 pp