BOUNDS FOR THE DERIVATIVE OF CERTAIN MEROMORPHIC FUNCTIONS AND ON MEROMORPHIC BLOCH-TYPE FUNCTIONS

被引:1
作者
Bhowmik, Bappaditya [1 ]
Sen, Sambhunath [1 ]
机构
[1] Indian Inst Technol Kharagpur, Dept Math, Kharagpur 721302, India
关键词
Bloch function; meromorphic function; Landau's reduction; Taylor coefficient; COEFFICIENTS;
D O I
10.21136/CMJ.2024.0332-23
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
It is known that if f is holomorphic in the open unit disc D of the complex plane and if, for some c > 0, vertical bar f (z)vertical bar <= 1/(1-vertical bar z vertical bar(2))(c), z is an element of D, then vertical bar f '(z)vertical bar <= 2(c + 1)/(1-vertical bar z vertical bar(2))(c+1). We consider a meromorphic analogue of this result. Furthermore, we introduce and study the class of meromorphic Bloch-type functions that possess a nonzero simple pole in D. In particular, we obtain bounds for the modulus of the Taylor coefficients of functions in this class.
引用
收藏
页码:397 / 414
页数:18
相关论文
共 20 条
[1]   Concerning the Bloch constant. [J].
Ahlfors, LV ;
Grunsky, H .
MATHEMATISCHE ZEITSCHRIFT, 1937, 42 :671-673
[2]  
ANDERSON JM, 1974, J REINE ANGEW MATH, V270, P12
[3]   Improved Bloch and Landau constants for meromorphic functions [J].
Bhowmik, Bappaditya ;
Sen, Sambhunath .
CANADIAN MATHEMATICAL BULLETIN-BULLETIN CANADIEN DE MATHEMATIQUES, 2023, 66 (04) :1269-1273
[4]   Landau and Bloch constants for meromorphic functions [J].
Bhowmik, Bappaditya ;
Sen, Sambhunath .
MONATSHEFTE FUR MATHEMATIK, 2023, 201 (02) :359-373
[5]  
Bloch A, 1924, CR HEBD ACAD SCI, V178, P2051
[6]  
Bloch A, 1925, Ann. Fac. Sci. Univ. Toulouse Sci. Math. Sci. Phys., V17, P1
[7]  
Bonk M., 1988, EXTREMALPROBLEME BEI
[8]   On Bloch's constant [J].
Chen, HH ;
Gauthier, PM .
JOURNAL D ANALYSE MATHEMATIQUE, 1996, 69 :275-291
[9]   SINGULAR MEASURES AND DOMAINS NOT OF SMIRNOV TYPE [J].
DUREN, PL ;
SHAPIRO, HS ;
SHIELDS, AL .
DUKE MATHEMATICAL JOURNAL, 1966, 33 (02) :247-&
[10]  
Graham I., 2003, Geometric Function Theory in One and Higher Dimensions