Equivariant decomposition of polynomial vector fields

Fahimeh Mokhtari; Jan A. Sanders

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arXiv · 1909.06955

Equivariant decomposition of polynomial vector fields

Fahimeh Mokhtari·Jan A. Sanders

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Abstract

To compute the unique formal normal form of families of vector fields with nilpotent linear part, we choose a basis of the Lie algebra consisting of orbits under the linear nilpotent. This creates a new problem: to find explicit formulas for the structure constants in this new basis. These are well known in the 2D case, and recently expressions were found for the 3D case by ad hoc methods. The goal of the present paper is to formulate a systematic approach to this calculation. We propose to do this using a rational method for the inversion of the Clebsch-Gordan coefficients. We illustrate the method on a family of 3D vector fields and compute the unique formal normal form for the Euler family both in the 2D and 3D case.

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BibTeX RIS

Fahimeh Mokhtari, Jan A. Sanders. 2019-09-04. Equivariant decomposition of polynomial vector fields. https://arxiv.org/abs/1909.06955

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