论文标题
所有矩形的有效决定性最大化
Efficient Determinant Maximization for All Matroids
论文作者
论文摘要
确定性最大化提供了许多领域的问题的优雅概括,包括凸几何,统计,机器学习,商品的公平分配和网络设计。在确定性最大化问题的情况下,我们获得了向量的集合$ v_1,\ ldots,v_n \ in \ mathbb {r}^d $,其目标是选择一个子集$ s \ subseteq [n]给定的给定量以最大程度地提高矩阵$ \ sum_ $ \ sum_ s的确定性。挑选的向量集$ s $必须满足某些组合约束,例如基数约束($ | s | \ leq k $)或矩阵约束($ s $是$ [n] $)定义的矩阵的基础。 在这项工作中,我们为在$ o(d^{o(d)})$的矩阵约束下提供了一个组合算法,以确保最大化问题 - 对于任何等级$ r \ geq d $的矩形的近似值。这补充了〜\ cite {brownlpst22}的最新结果,该结果依赖于确定因素的几何解释,对等级$ r \ leq d $的矩阵获得了相似的结合。我们的结果匹配了最著名的估计算法〜\ cite {madan2020maximization}的问题,这可以估算客观值,但无法提供具有类似保证的近似解决方案。我们的工作遵循〜\ cite {brownlpst22}开发的框架,该框架使用基于Matroid相交的算法来确定性最大化。为了克服对目标缺乏简单的几何解释,当$ r \ geq d $时,我们的方法将组合优化的想法与决定因素的代数属性相结合。我们还批判性地使用了〜\ cite {madan2020maximization}引入的问题的凸编程放松的属性。
Determinant maximization provides an elegant generalization of problems in many areas, including convex geometry, statistics, machine learning, fair allocation of goods, and network design. In an instance of the determinant maximization problem, we are given a collection of vectors $v_1,\ldots, v_n \in \mathbb{R}^d$, and the goal is to pick a subset $S\subseteq [n]$ of given vectors to maximize the determinant of the matrix $\sum_{i \in S} v_iv_i^\top$, where the picked set of vectors $S$ must satisfy some combinatorial constraint such as cardinality constraint ($|S| \leq k$) or matroid constraint ($S$ is a basis of a matroid defined on $[n]$). In this work, we give a combinatorial algorithm for the determinant maximization problem under a matroid constraint that achieves $O(d^{O(d)})$-approximation for any matroid of rank $r\geq d$. This complements the recent result of~\cite{BrownLPST22} that achieves a similar bound for matroids of rank $r\leq d$, relying on a geometric interpretation of the determinant. Our result matches the best-known estimation algorithms~\cite{madan2020maximizing} for the problem, which could estimate the objective value but could not give an approximate solution with a similar guarantee. Our work follows the framework developed by~\cite{BrownLPST22} of using matroid intersection based algorithms for determinant maximization. To overcome the lack of a simple geometric interpretation of the objective when $r \geq d$, our approach combines ideas from combinatorial optimization with algebraic properties of the determinant. We also critically use the properties of a convex programming relaxation of the problem introduced by~\cite{madan2020maximizing}.