Simplifying matrix differential equations with general coefficients
Autor: | Tsui, Man Cheung |
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Rok vydání: | 2022 |
Předmět: | |
Druh dokumentu: | Working Paper |
Popis: | We show that the $n\times n$ matrix differential equation $\delta(Y)=AY$ with $n^2$ general coefficients cannot be simplified to an equation in less than $n$ parameters by using gauge transformations whose coefficients are rational functions in the matrix entries of $A$ and their derivatives. Our proof uses differential Galois theory and a differential analogue of essential dimension. We also bound the minimum number of parameters needed to describe some generic Picard-Vessiot extensions. Comment: 13 pages. Corrected miscitation of [1] on page 5; added Example 2.2; small grammatical change |
Databáze: | arXiv |
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