Conditions for convexity of a derivative and some applications to the Gamma function

被引:0
|
作者
Merkle M. [1 ]
机构
[1] University of Belgrade, Faculty of Electrical Engineering, Department of Applied Mathematics, 11120 Belgrade
关键词
Convexity; Gamma function; Inequalities; Schur-convexity;
D O I
10.1007/s000100050036
中图分类号
学科分类号
摘要
We consider necessary and sufficient conditions for the convexity of a function x f′(x) in terms of some properties of the associated function of two variables F (x,y) = (f (y) - f(x))/(y - x)- In particular, we prove that f′ is convex if and only if F is convex and if and only if F is Schur-convex. These results are applied to the theory of the Gamma function. We complement a characterization of the Gamma function due to H. Kairies and present some inequalities for the ratio of Gamma functions. © Birkhäuser Verlag, Basel, 1998.
引用
收藏
页码:273 / 280
页数:7
相关论文
共 50 条
  • [1] THE GEOMETRIC CONVEXITY OF A FUNCTION INVOLVING GAMMA FUNCTION WITH APPLICATIONS
    Chu, Yuming
    Zhang, Xiaoming
    Zhang, Zhihua
    COMMUNICATIONS OF THE KOREAN MATHEMATICAL SOCIETY, 2010, 25 (03): : 373 - 383
  • [2] Convexity in the Theory of the Gamma Function
    Merkle, Milan
    INTERNATIONAL JOURNAL OF APPLIED MATHEMATICS & STATISTICS, 2007, 11 (N07): : 103 - 117
  • [3] ON MODULI OF CONVEXITY AND SOME APPLICATIONS
    Barcenas, Diomedes
    Sanchez, Luisa
    QUAESTIONES MATHEMATICAE, 2009, 32 (03) : 307 - 319
  • [4] Convexity, Schur-convexity and bounds for the gamma function involving the digamma function
    Merkle, M
    ROCKY MOUNTAIN JOURNAL OF MATHEMATICS, 1998, 28 (03) : 1053 - 1066
  • [5] Convexity and q-gamma function
    Elezović N.
    Giordano C.
    Pečarić J.
    Rendiconti del Circolo Matematico di Palermo, 1999, 48 (2) : 285 - 298
  • [7] Some sufficient conditions for starlikeness and convexity
    Nunokawa, Mamoru
    Owa, Shigeyoshi
    Polatoglu, Yasar
    Caglar, Mert
    Duman, Emel Yavuz
    TURKISH JOURNAL OF MATHEMATICS, 2010, 34 (03) : 333 - 337
  • [8] Abstract convexity, some relations and applications
    Llinares, JV
    OPTIMIZATION, 2002, 51 (06) : 797 - 818
  • [9] Convexity of the gamma function with respect to Holder means
    Trif, T
    INEQUALITY THEORY AND APPLICATIONS VOL 3, 2003, : 189 - 195
  • [10] Convexity Properties And Inequalities For A Generalized Gamma Function
    Krasniqi, Valmir
    Shabani, Armend Sh.
    APPLIED MATHEMATICS E-NOTES, 2010, 10 : 27 - 35