Structure and arithmetic of multivariate Ore extensions
André Leroy, Huda Merdach
TL;DR
The paper develops the structure theory of multivariable Ore extensions $S= A[\\underline{t}; \\sigma,\\underline{\\delta}]$, introducing pseudo-multilinear transformations (PMT) that realize $S$-actions on left $A$-modules and connect to the evaluation of polynomials in $S$. It establishes a general product formula and uses PMTs to characterize the root sets $V(f)$ via conjugacy classes, while also analyzing the center, semi-invariant polynomials, and centralizers. The results extend univariate skew-polynomial theory to the multivariable setting and provide a framework for studying module morphisms, root decompositions, and centralizer structures, with potential connections to noncommutative algebra and coding theory. The approach unifies evaluation, conjugation, and module-theoretic perspectives, offering tools to analyze roots and morphisms in multivariate noncommutative polynomial rings.
Abstract
We give the basic structure of the multivariable Ore extensions $S=A[\underline{t} ; σ, \underlineδ]$ introduced in the work of Martínez-Peñas and Kschischang. The Pseudo multilinear transformations (PMT's) are introduced and correspond to modules over $S$. These maps are strongly connected to the evaluation of polynomials in $S$. A general product formula is obtained. PMT's help to put some structure on the set of roots of a polynomial $f(t) \in S$.
