The second derivative of a meromorphic function

Authors
Citation
Jk. Langley, The second derivative of a meromorphic function, P EDIN MATH, 44, 2001, pp. 455-478
Citations number
31
Categorie Soggetti
Mathematics
Journal title
PROCEEDINGS OF THE EDINBURGH MATHEMATICAL SOCIETY
ISSN journal
00130915 → ACNP
Volume
44
Year of publication
2001
Part
3
Pages
455 - 478
Database
ISI
SICI code
0013-0915(200110)44:<455:TSDOAM>2.0.ZU;2-P
Abstract
Let f be meromorphic of finite order in the plane, such that f(k) has finit ely many zeros, for some k greater than or equal to 2. The author has conje ctured that f then has finitely many poles. In this paper, we strengthen a previous estimate for the frequency of distinct poles of f. Further, we sho w that the conjecture is true if either (i) f has order less than 1 + epsilon, for some positive absolute constant epsilon, or (ii) f((m)), for some 0 less than or equal to m < k, has few zeros away fro m the real axis.