For online matching with the line metric, we present a lower bound of $\Omega(\log n)$ on the approximation ratio of any online (possibly randomized) algorithm. This beats the previous best lower bound of $\Omega(\sqrt{\log n})$ and matches the known upper bound of $O(\log n)$.

翻译：对于在线匹配直线度, 我们根据任何在线( 可能随机化) 算法的近似比, 显示一个较低约束值$\ Omega( log n) 。 这比上一个最低约束值$\ Omega(\ sqrt\log n}), 和已知最高约束值$O( log n) 相匹配 。