Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-19T13:44:40.005Z Has data issue: false hasContentIssue false

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 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

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