Acta mathematica scientia, Series B >
UNIQUENESS RESULTS OF MEROMORPHIC FUNCTIONS WHOSE DERIVATIVES SHARE FOUR SMALL FUNCTIONS
Received date: 2010-04-26
Revised date: 2011-07-28
Online published: 2012-07-20
Supported by
This work is supported by the NSFC (11171184), the NSFC (10771121), the NSFC & RFBR (Joint Project) (10911120056), the NSFC (40776006), the NSF of Shandong Province, China (Z2008A01), and the NSF of Shandong Province, China (ZR2009AM008).
We prove an oscillation theorem of two meromorphic functions whose deriva-tives share four values IM. From this we obtain some uniqueness theorems, which improve the corresponding results given by Yang [16] and Qiu [10], and supplement results given by
Nevanlinna [9] and Gundersen [3, 4]. Some examples are provided to show that the results in this paper are best possible.
Key words： Nevanlinna theory; meromorphic function; shared value; uniqueness; order of growth
LI Xiao-Min , YI Hong-Xun , HU Hai-Yan . UNIQUENESS RESULTS OF MEROMORPHIC FUNCTIONS WHOSE DERIVATIVES SHARE FOUR SMALL FUNCTIONS[J]. Acta mathematica scientia, Series B, 2012 , 32(4) : 1593 -1606 . DOI: 10.1016/S0252-9602(12)60126-X
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