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arXiv · 2512.24216

General Zakharov-Shabat equations without Lax operators

Masatoshi Noumi·Takashi Takebe
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Abstract

The operators in the Zakharov-Shabat equations of integrable hierarchies are usually defined from the Lax operators. In this article it is shown that the Zakharov-Shabat equations themselves recover the Lax operators under suitable change of independent variables in the case of the KP hierarchy and the modified KP hierarchy (in the matrix formulation).

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Masatoshi Noumi, Takashi Takebe. 2025-12-30. General Zakharov-Shabat equations without Lax operators. https://arxiv.org/abs/2512.24216

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