Work

Isomonodromic Deformations for Linear $q$-Difference Systems of Degree One

Year: 2026
Type: preprint
Abstract: We construct isomonodromy transformations for linear $q$-difference systems of the form $Y(qz)=A(z)Y(z)$, where $A(z)=A_0+z A_1$ has diagonal leading coefficient. These transformations shift eigenvalues of the leading coefficient $A_1$ together with roots of $\det A(z)$. They lift compatibility to the right eigenpairs of $A(z)$, yielding a discrete local tau function. The resulting deformation equations preserve the Birkhoff connection matrix, and reduce in their $q\to 1$ limit to the isomonodromic deformation of a meromorphic connection on $\mathbb P^1$ with an irregular singularity of Poincaré rank one at $\infty$.
Author: Ma, Yiming
Institution: Peking University
Language: English
Open Access status: green
OpenAlex ID: W7208715250
Cites: 3
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Related to: 10