论文标题
不完整的伽马功能上的上下界限
Exact lower and upper bounds on the incomplete gamma function
论文作者
论文摘要
不完整的伽玛函数$γ(a,x)$的下限和上限$ b_a(x)$均为所有实际$ a $和所有实际$ x> 0 $提供。这些边界$ b_a(x)$在某种意义上是确切的,从某种意义上说,$ b_a(x)\ underSet {x \ downarrow0} \simγ(a,x)$和$ b_a(x)\ underSet {x \ to \ infty} \ infty} \simγ(a,x)$。此外,对于其他$ x $的其他值,这些边界的相对错误距离$ 0 $和$ \ infty $相当小。
Lower and upper bounds $B_a(x)$ on the incomplete gamma function $Γ(a,x)$ are given for all real $a$ and all real $x>0$. These bounds $B_a(x)$ are exact in the sense that $B_a(x)\underset{x\downarrow0}\simΓ(a,x)$ and $B_a(x)\underset{x\to\infty}\simΓ(a,x)$. Moreover, the relative errors of these bounds are rather small for other values of $x$, away from $0$ and $\infty$.