Abstract
We continue the work of Szegő [18] on describing the angular distribution of the zeros of the normalized partial sum s n(nz) of e z, where \(s _{n}(z):={\sum _{k=0} ^{n}}z ^k/k!\). We imbed this problem in some inverse problem of potential theory and prove a so-called Erdős-Turán-type theorem, which is of interest in itself.
Similar content being viewed by others
References
V. V. Andrievskii, V. I. Belyi and V. K. Dzjadyk, Conformal Invariants in Constructive Theory of Functions of Complex Variable, Atlanta, Georgia, World Federation Publisher, 1995.
V. V. Andrievskii and H. -P. Blatt, Discrepancy of Signed Measures and Polynomial Approximation, Berlin/New York, Springer-Verlag, 2002.
H.-P. Blatt, On the distribution of simple zeros of polynomials, J. Approx. Theory 69 (1992), 250–268.
H.-P. Blatt and R. Grothmann, Erdős-Turán theorems on a system of Jordan curves and arcs, Constr. Approx. 7 (1991), 19–47.
H.-P. Blatt and H. N. Mhaskar, A general discrepancy theorem, Ark. Mat. 31 (1993), 219–246.
H.-P. Blatt, E. B. Saff and V. Totik, The distribution of extreme points in best complex polynomial approximation, Constr. Approx. 5 (1989), 357–370.
J. D. Buckholtz, A characterization of the exponential series, Amer. Math. Monthly 73 Part II (1966), 121–123.
A. J. Carpenter, R. S. Varga and J. Waldvogel, Asymptotics for the zeros of partial sums of e z, I, Rocky Mountain J. 21 (1991), 99–120.
P. Erdős and P. Turán, On the uniformly-dense distribution of certain sequences of points, Annals of Math. 41 (1940), 162–173.
P. Erdős and P. Turán, On a problem in the theory of uniform distribution, I and II, Indag. Math. 10 (1948), 370–378, 406–413.
P. Erdős and P. Turán, On the distribution of roots of polynomials, Annals of Math. 51 (1950), 105–119.
G. M. Goluzin, Geometric Theory of Functions of a Complex Variable, (in Russian), Moscow, Nauka, 1966.
O. Lehto and K. I. Virtanen, Quasiconformal Mappings in the Plane, 2nd ed., Berlin, Springer-Verlag, 1973.
H. N. Mhaskar, Some discrepancy theorems, in: E. B. Saff (ed.), Approximation Theory, Tampa, Springer Lecture Notes 1287 Berlin, Springer Verlag, (1987), 117–131.
Ch. Pommerenke, Boundary Behaviour of Conformal Maps, New York/Berlin, Springer Verlag, 1992.
I. E. Pritsker and R. S. Varga, The Szegő curve, zero distribution and weighted approximation, Trans. Amer. Math. Soc. 349 (1997), 4085–4105.
E. B. Saff and V. Totik, Logarithmic Potentials with External Fields, New York/Berlin, Springer Verlag, 1997.
G. Szegő, Über eine Eigenschaft der Exponentialreihe, Sitzungsber. Berl. Math. Ges. 23 (1924), 50–64.
V. Totik, Distribution of simple zeros of polynomials, Acta Math. 170 (1993), 1–28.
M. Tsuji, Potential Theory in Modern Function Theory, New York, Chelsea, 1950.
R. S. Varga, A. J. Carpenter and B. W. Lewis, The dynamical movements of the zeros of the normalized zeros of the partial sums of exp(z), to appear in Electronic Transactions on Numerical Analysis (ETNA).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Andrievskii, V.V., Carpenter, A.J. & Varga, R.S. Angular Distribution of Zeros of the Partial Sums of ez via the Solution of Inverse Logarithmic Potential Problem. Comput. Methods Funct. Theory 6, 447–458 (2006). https://doi.org/10.1007/BF03321622
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF03321622