Landau定理中上界的一个改进

摘要

通过相关文献给出的穿孔平面C{0,1}的双曲度量的密度函数的新的下界估计,借助广义Schwarz 引理我们对Landau 定理中关于上界做了进一步改进并得到了一个带参数的上界表达式。并且当参数取到0时,此结论正好为相关文献得到的结果。%On the basis of the lower bound of the Poincar´e density of the twice-punctured plane C{0, 1}which was given in related literature, we improve the upper bounder expression of Landau theorem and obtain a new upper bounder expression with a parameter by Schwarz Lemma. Moreover, the expression is the result in related literature when the parameter is zero.