【摘要】 <正> 设f（z）=z+sum from n=2 to ∞(a_nz∈S,则Biberbach猜想|a_n|≤n对一切n成立。对n=4的Bieberbach猜想迄今为止已有多种证明,它们都可引出|a₄|依赖于|a₂|的估计式。目前最好的结果为更多还原

【Abstract】 In this paper, as an application of the Szego inequality, we improved the estimate for the forth coefficients of univalent functions in terms of second coefficients and obtained the following theorem:Theorem. If f (z)=z+sum from n=2 to ∞(a_nz~n)∈S, then更多还原