Abstract
We consider real polynomials in one variable without vanishing coefficients, with all roots real and of distinct moduli. We show that the signs of the coefficients define the order of the moduli of the roots on the real positive half-line exactly when no four consecutive signs of coefficients equal \((+,+,-,-)\), \((-,-,+,+)\), \((+,-,-,+)\) or \((-,+,+,-)\).
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References
Albouy, A., Fu, Y.: Some remarks about Descartes’ rule of signs. Elem. Math. 69, 186–194 (2014)
Anderson, A., Jackson, J., Sitharam, M.: Descartes’ rule of signs revisited. Am. Math. Mon. 105, 447–451 (1998)
Cajori, F.: A history of the arithmetical methods of approximation to the roots of numerical equations of one unknown quantity. Colo. Coll. Publ. Sci. Ser. 12–7, 171–215 (1910)
Cheriha, H., Gati, Y., Kostov, V.P.: A nonrealization theorem in the context of Descartes’ rule of signs, Annual of Sofia University “St. Kliment Ohridski’’. Fac. Math. Inf. 106, 25–51 (2019)
Curtiss, D.R.: Recent extensions of Descartes’ rule of signs. Ann. Math. 19(4), 251–278 (1918)
de Gua de Malves, J.-P.: Démonstrations de la Règle de Descartes, Pour connoître le nombre des Racines positives & négatives dans les Équations qui n’ont point de Racines imaginaires, Memoires de Mathématique et de Physique tirés des registres de l’Académie Royale des Sciences 72-96 (1741)
Forsgård, J., Kostov, V.P., Shapiro, B.: Could René Descartes have known this? Exp. Math. 24(4), 438–448 (2015)
Forsgård, J., Novikov, D., Shapiro, B.: A tropical analog of Descartes’ rule of signs. Int. Math. Res. Not. IMRN 12, 3726–3750 (2017)
Fourier, J.: Sur l’usage du théorème de Descartes dans la recherche des limites des racines. Bulletin des sciences par la Société philomatique de Paris 156–165, 181–187 (1820); œuvres 2, 291–309, Gauthier- Villars, 1890
Gauss, C.F.: Beweis eines algebraischen Lehrsatzes. J. Reine Angew. Math. 3, 1–4 (1828); Werke 3, 67–70, Göttingen, (1866)
Grabiner, D.J.: Descartes’ rule of signs: another construction. Am. Math. Mon. 106, 854–856 (1999)
Jensen, J.L.W.: Recherches sur la théorie des équations. Acta Math. 36, 181–195 (1913)
Kostov, V.P.: Topics on hyperbolic polynomials in one variable. Panoramas et Synthèses 33 vi \(+\) 141 p. SMF 2011
Kostov, V.P.: On realizability of sign patterns by real polynomials. Czechoslov. Math. J. 68(3), 853–874 (2018)
Kostov, V.P.: Polynomials, sign patterns and Descartes’ rule of signs. Math. Bohem. 144(1), 39–67 (2019)
Kostov, V.P.: Descartes’ rule of signs and moduli of roots. Publ. Math. Debr. 96(1–2), 161–184 (2020). https://doi.org/10.5486/PMD.2020.8640
Kostov, V.P.: Hyperbolic polynomials and canonical sign patterns. Serdica Math. J. 46, 135–150 (2020)
Kostov, V.P.: Univariate polynomials and the contractibility of certain sets, Annual of Sofia University “St. Kliment Ohridski’’. Fac. Math. Inf. 107, 11–35 (2020)
Kostov, V.P.: Hyperbolic polynomials and rigid moduli orders. Publ. Math. Debr. 100(1–2), 119–128 (2022). https://doi.org/10.5486/PMD.2022.9068
Kostov, V.P.: The disconnectedness of certain sets defined after uni-variate polynomials. Constr. Math. Anal. 5(3), 119–133 (2022)
Laguerre, E.: Sur la théorie des équations numériques œuvres 1, Paris: Chelsea. New-York 1972, 3–47 (1898)
Laguerre, E.: Sur la théorie des équations numériques. Journal de Mathématiques pures et appliquées 3(9), 99–146 (1883)
Meserve, B.E.: Fundamental Concepts of Algebra. Dover Publications, New York (1982)
The Geometry of René Descartes with a facsimile of the first edition, translated by D. E. Smith and M.L. Latham. Dover Publications, New York (1954)
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Kostov, V.P. Which Sign Patterns are Canonical?. Results Math 77, 235 (2022). https://doi.org/10.1007/s00025-022-01769-3
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DOI: https://doi.org/10.1007/s00025-022-01769-3