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Duality between loci of complex polynomials and the zeros of polar derivatives

Published online by Cambridge University Press:  12 April 2018

BLAGOVEST SENDOV
Affiliation:
Bulgarian Academy of Sciences, Institute of Information and Communication Technologies, Acad. G. Bonchev Str., bl. 25A, 1113 Sofia, Bulgaria. e-mail: [email protected]
HRISTO SENDOV
Affiliation:
Department of Statistical and Actuarial Sciences, Western University, 1151 Richmond Str., London, ON, N6A 5B7, Canada. e-mail: [email protected]

Abstract

This work investigates the connections between the notion of a locus of a complex polynomial and the polar derivatives. Polar differentiation extends classical derivatives and provides additional flexibility. The notion of a locus was introduced in [8] and proved useful in providing sharp versions of several classical results in the area known as Geometry of Polynomials. The investigations culminated in the work [11]. A need was revealed for a unified treatment of bounded and unbounded loci of polynomials of degree at most n as well as a unified treatment of polar derivatives and ordinary derivatives. This work aims at providing such a framework.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 2018 

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Footnotes

Partially supported by Bulgarian National Science Fund #DTK 02/44.

Partially supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada.

References

REFERENCES

[1] Fekete, M. Über Gebiete, in denen komplexe Polynome jeden Wert zwischen zwei gegebenen annehmen, Math. Z. 22 (1925), 17.Google Scholar
[2] Grace, J.H. The zeros of a polynomial. Proc. Camb. Philos. Soc. 11 (1902), 352357.Google Scholar
[3] Heawood, P.J. Geometrical relations between the roots of f(x) = 0 and f'(x) = 0. Q. J. Math. 38 (1907), 84107.Google Scholar
[4] London, D. On a connection between the permanent function and polynomials. Linear and Multilinear Algebra. 1 (1973), 231240.Google Scholar
[5] Plauman, D. and Putinar, M. A relative Grace theorem for complex polynomials. Math. Proc. Camb. Phil. Soc. 161 (2016), 1730.Google Scholar
[6] Pólya, G. and Szegö, G. Problems and Theorems in Analysis, Volume II (Springer-Verlag, 1976).Google Scholar
[7] Rahman, Q.I. and Schmeisser, G. Analytic Theory of Polynomials (Oxford Univ. Press Inc., New York, 2002).Google Scholar
[8] Sendov, Bl. and Sendov, H. Loci of complex polynomials, part I. Trans. Amer. Math. Soc. 10 (366) (2012), 51555184.Google Scholar
[9] Sendov, Bl. and Sendov, H.S. Loci of complex polynomials, part II: polar derivatives. Math. Proc. Camb. Phil. Soc. 159 (2015), 253273.Google Scholar
[10] Sendov, Bl. and Sendov, H.S. Two Walsh-type theorems for the solutions of multi-affine symmetric polynomials, In Progress in Approximation Theory and Applicable Complex Analysis: In Memory of Q.I. Rahman, (Govil, N., Mohapatra, R., Qazi, M., Schmeisser, G. eds.) (Springer Optimisation and Its Applications, vol. 117 (2017), pp. 145162.Google Scholar
[11] Sendov, Bl. and Sendov, H.S. Stronger Rolle's theorem for complex polynomials, submitted, (2016).Google Scholar
[12] Sendov, Bl. and Sendov, H.S. On the zeros and critical points of polynomials with non-negative coefficients: a non-convex analogue of the Gauss–Lucas theorem, to appear in Constr. Approx. (2017), DOI 10.1007/s00365-017-9374-6Google Scholar
[13] Szegő, G. Bemerkungen zu einem Satz von J. H. Grace uber die Wurzeln algebraischer Gleichungen. Math. Z. 13 (1922), 2855.Google Scholar