发表机构
University of Oxford(牛津大学)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
本文证明了$k$-server猜想,通过将工作函数表示为矩阵并利用行列式与势函数进行摊销分析,证明工作函数算法在任意度量空间上达到竞争比$k$。
AI 中文摘要
$k$-server猜想指出,在任意度量空间上,确定性在线算法可以达到竞争比$k$。我们证明了该猜想。具体而言,我们证明了工作函数算法满足该猜想。我们的证明利用了工作函数的一种自然代数表示,将其视为一个矩阵,该矩阵编码了到达某个配置的所有可行路径。在这种表示中,最优成本定义中出现的最小值和加法运算分别对应于形式表达式的加法和乘法,而每个工作函数值对应于矩阵$k$列的行列式。请求到达通过基变换和行替换更新该表示。摊销分析基于一个势函数,该势函数由一个更大的矩阵定义,其坐标是原始矩阵表示坐标的坐标对。
英文摘要
The $k$-server conjecture states that a deterministic online algorithm can achieve competitive ratio $k$ on every metric space. We prove the conjecture. Specifically, we show that the work function algorithm satisfies it. Our proof uses a natural algebraic representation of the work function as a matrix, which encodes all feasible paths to reach a configuration. In this representation, the minimum and addition operations arising in the definition of optimal costs correspond to addition and multiplication of formal expressions, and each work function value corresponds to the determinant of $k$ columns of the matrix. A request arrival updates the representation via a change of basis and row replacement. The amortized analysis is based on a potential function defined in terms of a larger matrix whose coordinates are pairs of coordinates of the original matrix representation.