一句话:综述如何利用算法设计进展,系统地证明电路复杂性等下界。
计算理论长期关注不可能性结果,尤其是证明某计算任务不存在高效算法。本文指出,计算机科学家非常擅长设计高效算法,却难以证明许多看似很弱的复杂性下界。作者介绍过去十年一条研究纲领:把算法设计中的知识系统化地用于证明复杂性下界。例如,更快的电路可满足性算法,即使只是略微优于穷举搜索,也能自动推出有趣函数的电路复杂性下界。文章为简短引言,详细内容见配套报告。
Since the beginning of the theory of computation, researchers have been fascinated by the prospect of proving impossibility results on computing. When and how can we argue that a task cannot be efficiently solved, no matter what algorithm we try to use?In this short article, I will briefly introduce some of the ideas behind a research program in computational complexity that I and others have studied, for the last decade. (The accompanying talk will contain more details.) The program begins with the observations that:(a) Computer scientists know a great deal about how to design efficient algorithms.(b) However, we do not know how to prove many weak-looking complexity lower bounds.It turns out that certain knowledge we have from (a) can be leveraged to prove complexity lower bounds in a systematic way, making progress on (b). For example, progress on faster circuit satisfiability algorithms (even those that barely improve upon exhaustive search) automatically imply circuit complexity lower bounds for interesting functions1.