منابع مشابه
Lattice Problems in NP ∩ coNP
We show that the problems of approximating the shortest and closest vector in a lattice to within a factor of √ n lie in NP intersect coNP. The result (almost) subsumes the three mutually-incomparable previous results regarding these lattice problems: Banaszczyk [7], Goldreich and Goldwasser [14], and Aharonov and Regev [2]. Our technique is based on a simple fact regarding succinct approximati...
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Informally, a language L has speedup if, for any Turing machine (TM) for L, there exists one that is better. Blum [2] showed that there are computable languages that have almost-everywhere speedup. These languages were unnatural in that they were constructed for the sole purpose of having such speedup. We identify a condition apparently only slightly stronger than P 6= NP which implies that acc...
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In this note we show that AMexp 6⊆ NP ∩ coNP/poly, where AMexp denotes the exponential version of the class AM. The main part of the proof is a collapse of EXP to AM under the assumption that EXP ⊆ NP ∩ coNP/poly
متن کاملThe Shrinking Property for NP and coNP
We study the shrinking and separation properties (two notions well-known in descriptive set theory) for NP and coNP and show that under reasonable complexity-theoretic assumptions, both properties do not hold for NP and the shrinking property does not hold for coNP. In particular we obtain the following results. 1. NP and coNP do not have the shrinking property, unless PH is finite. In general,...
متن کاملLecture 4 : More NP - completeness , NP - search , coNP
We first observe that NP-completeness immediately follows forCNFSAT and SAT since 3SAT ≤p CNFSAT ≤p SAT . Note that 3SAT ⊂ CNFSAT ⊂ SAT . The reduction in each case is almost the identity (though of course it can’t be since the sets are different). The only issue is that we have to modify satisfiable formulas that are not in 3CNF. For the 3SAT ≤p CNFSAT reduction we simply map any input that is...
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ژورنال
عنوان ژورنال: Journal of the ACM
سال: 2005
ISSN: 0004-5411,1557-735X
DOI: 10.1145/1089023.1089025