Inequalities and monotonicity properties for the gamma function

被引:25
作者
Giordano, C
Laforgia, A
机构
[1] Univ Turin, Dipartimento Matemat, I-10123 Turin, Italy
[2] Univ Roma Tre, Dipartimento Matemat, Rome, Italy
关键词
gamma function; inequality; ultraspherical polynomials;
D O I
10.1016/S0377-0427(00)00659-2
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
We present a survey of some recent results on the ratio of two gamma functions and prove the following inequalities for the product: 1/2 r(1 + x(1) + x(2)) less than or equal to r(1 + x(1))r(1 + x(2)) < r(1 + x(1) + x(2)) for x(1),x(2) > 0 and x(1).x(2) = 1. Finally, we study the possible extension to k variables of the lower bound above. (C) 2001 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:387 / 396
页数:10
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