Abstract
The behavior of closed polynomials, i.e., polynomials \( f \in \Bbbk [x_1 , \ldots ,x_n ]\backslash \Bbbk \) such that the subalgebra \( \Bbbk [f] \) is integrally closed in \( \Bbbk [x_1 , \ldots ,x_n ] \) , is studied under extensions of the ground field. Using some properties of closed polynomials, we prove that, after shifting by constants, every polynomial \( f \in \Bbbk [x_1 , \ldots ,x_n ]\backslash \Bbbk \) can be factorized into a product of irreducible polynomials of the same degree. We consider some types of saturated subalgebras \( A \subset \Bbbk [x_1 , \ldots ,x_n ] \) , i.e., subalgebras such that, for any \( f \in A\backslash \Bbbk \) , a generative polynomial of f is contained in A.
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Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 59, No. 12, pp. 1587–1593, December, 2007.
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Arzhantsev, I.V., Petravchuk, A.P. Closed polynomials and saturated subalgebras of polynomial algebras. Ukr Math J 59, 1783–1790 (2007). https://doi.org/10.1007/s11253-008-0037-4
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DOI: https://doi.org/10.1007/s11253-008-0037-4