English

How one can repair non-integrable Kahan discretizations

Exactly Solvable and Integrable Systems 2023-03-29 v1 Mathematical Physics math.MP

Abstract

Kahan discretization is applicable to any system of ordinary differential equations on Rn\mathbb R^n with a quadratic vector field, x˙=f(x)=Q(x)+Bx+c\dot{x}=f(x)=Q(x)+Bx+c, and produces a birational map xx~x\mapsto \widetilde{x} according to the formula (x~x)/ϵ=Q(x,x~)+B(x+x~)/2+c(\widetilde{x}-x)/\epsilon=Q(x,\widetilde{x})+B(x+\widetilde{x})/2+c, where Q(x,x~)Q(x,\widetilde{x}) is the symmetric bilinear form corresponding to the quadratic form Q(x)Q(x). When applied to integrable systems, Kahan discretization preserves integrability much more frequently than one would expect a priori, however not always. We show that in some cases where the original recipe fails to preserve integrability, one can adjust coefficients of the Kahan discretization to ensure its integrability.

Keywords

Cite

@article{arxiv.2003.12596,
  title  = {How one can repair non-integrable Kahan discretizations},
  author = {Matteo Petrera and Yuri B. Suris and René Zander},
  journal= {arXiv preprint arXiv:2003.12596},
  year   = {2023}
}

Comments

6 pp

R2 v1 2026-06-23T14:29:44.843Z