Noncommutative discrete equations, symmetries and reductions

Pavlos Xenitidis

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arXiv · 2507.04472

Noncommutative discrete equations, symmetries and reductions

Pavlos Xenitidis

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Abstract

Employing the Lax pairs of the noncommutative discrete potential Korteweg--de Vries (KdV) and Hirota's KdV equations, we derive differential--difference equations that are consistent with these systems and serve as their generalised symmetries. Miura transformations mapping these equations to a noncommutative modified Volterra equation and its master symmetry are constructed. We demonstrate the use of these symmetries to reduce the potential KdV equation, leading to a noncommutative discrete Painlev{\`{e}} equation and to a system of partial differential equations that generalises the Ernst equation and the Neugebauer--Kramer involution. Additionally, we present a Darboux transformation and an auto-B\"acklund transformation for the Hirota KdV equation, and establish their connection with the noncommutative Yang--Baxter map $F_{III}$.

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Pavlos Xenitidis. 2025-07-06. Noncommutative discrete equations, symmetries and reductions. https://arxiv.org/abs/2507.04472

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