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arXiv 0811.3161cs.CC
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深度3恒等式的一个几乎最优秩界

An Almost Optimal Rank Bound for Depth-3 Identities

Nitin Saxena, C. Seshadhri

摘要:

我们证明了一个简单的、最小的和零的深度为3的回路(在任何域上)的秩至多为k^3 \log d。以前已知的最佳秩界是2^{O(k^2)}(\log d)^{k-2},由Dvir和Shpilka(STOC 2005)提出。这几乎解决了Dvir和Shpilka首先提出的秩问题(因为我们还提供了秩Ω(k \log d)的简单和最小的恒等式)。我们的秩界显著改进了Karnin和Shpilka(CCC 2008)对深度3电路的最著名的确定性黑盒身份测试(对k的依赖性呈指数下降)。我们的技术还揭示了非零深度3电路的因式分解模式,最引人注目的是:一个简单的,最小的和非零深度3电路(在任何领域)的线性因子的秩最多是k^3 \log d。这项工作的新特点是一个新的概念之间的映射集的线性形式,称为“理想匹配”,用于研究深度3电路。我们证明有趣的结构结果深度3身份使用这些技术。我们相信,这些可以导致这些电路的确定性多项式时间身份测试的目标。

英文摘要:

We show that the rank of a depth-3 circuit (over any field) that is simple, minimal and zero is at most k^3\log d. The previous best rank bound known was 2^{O(k^2)}(\log d)^{k-2} by Dvir and Shpilka (STOC 2005). This almost resolves the rank question first posed by Dvir and Shpilka (as we also provide a simple and minimal identity of rank Ω(k\log d)). Our rank bound significantly improves (dependence on k exponentially reduced) the best known deterministic black-box identity tests for depth-3 circuits by Karnin and Shpilka (CCC 2008). Our techniques also shed light on the factorization pattern of nonzero depth-3 circuits, most strikingly: the rank of linear factors of a simple, minimal and nonzero depth-3 circuit (over any field) is at most k^3\log d. The novel feature of this work is a new notion of maps between sets of linear forms, called "ideal matchings", used to study depth-3 circuits. We prove interesting structural results about depth-3 identities using these techniques. We believe that these can lead to the goal of a deterministic polynomial time identity test for these circuits.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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