期刊名称：Electronic Colloquium on Computational Complexity
印刷版ISSN：1433-8092
出版年度：2010
卷号：2010
出版社：Universität Trier, Lehrstuhl für Theoretische Computer-Forschung
摘要：We prove that relative to an oracle, there is no worst-case to average-case reduction for NP. We also handle classes that are somewhat larger than NP, as well as worst-case to errorless-average-case reductions. In fact, we prove that relative to an oracle, there is no worst-case to errorless-average-case reduction from NP to Missing argument for \text. The latter class contains Missing argument for \text and captures the power of randomized computations conditioned on efficiently testable events. We also handle reductions from NP to the polynomial-time hierarchy and beyond, under restrictions on the number of queries the reductions can make.
