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Sommes de trois carrés de fractions en deux variables

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Abstract.

This paper extends previous works by Cassels-Ellison-Pfister and Christie in producing different collections of positive polynomials in ℝ[X,Y] which are not sums of three squares of rational fractions. The results are essentially obtained in extending methods of Galois descent for positivity of the ℝ(X)-rank of special kinds of elliptic curves.

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Macé, O., Mahé, L. Sommes de trois carrés de fractions en deux variables. manuscripta math. 116, 421–447 (2005). https://doi.org/10.1007/s00229-004-0535-0

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  • DOI: https://doi.org/10.1007/s00229-004-0535-0

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