{"title":"通用的分离","authors":"L. Fortnow, T. Yamakami","doi":"10.1109/SCT.1994.315809","DOIUrl":null,"url":null,"abstract":"M. Blum and R. Impagliazzo (Proc. 28th IEEE Symposium on Foundations of Computer Science, pp. 118-126, 1987), using techniques of Hartmanis and Hemachandra (1991) and Rackoff (1982), showed that if P = NP then P(G) = NP(G)/spl cap/co-NP(G) = UP(G), where G is a generic oracle. They left open the question as to whether these collapses occur at higher levels of the polynomial-time hierarchy. We give a surprising negative answer to this question. We show that relative to any generic oracle G and for any k/spl ges/ 2, there exists a tally set in U/spl Deltasub ksup P/(G)/spl capspl Pisub ksup P/(G) but not in /spl Deltasub ksup P/(G). An immediate corollary is that generic oracles separate /spl Sigmasub ksup Pspl capspl Pisub ksup P/ and /spl Deltasub ksup P/. We also show that related results hold for type-2 complexity.<<ETX>>","PeriodicalId":386782,"journal":{"name":"Proceedings of IEEE 9th Annual Conference on Structure in Complexity Theory","volume":"1 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1996-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"9","resultStr":"{\"title\":\"Generic separations\",\"authors\":\"L. Fortnow, T. Yamakami\",\"doi\":\"10.1109/SCT.1994.315809\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"M. Blum and R. Impagliazzo (Proc. 28th IEEE Symposium on Foundations of Computer Science, pp. 118-126, 1987), using techniques of Hartmanis and Hemachandra (1991) and Rackoff (1982), showed that if P = NP then P(G) = NP(G)/spl cap/co-NP(G) = UP(G), where G is a generic oracle. They left open the question as to whether these collapses occur at higher levels of the polynomial-time hierarchy. We give a surprising negative answer to this question. We show that relative to any generic oracle G and for any k/spl ges/ 2, there exists a tally set in U/spl Deltasub ksup P/(G)/spl capspl Pisub ksup P/(G) but not in /spl Deltasub ksup P/(G). An immediate corollary is that generic oracles separate /spl Sigmasub ksup Pspl capspl Pisub ksup P/ and /spl Deltasub ksup P/. We also show that related results hold for type-2 complexity.<<ETX>>\",\"PeriodicalId\":386782,\"journal\":{\"name\":\"Proceedings of IEEE 9th Annual Conference on Structure in Complexity Theory\",\"volume\":\"1 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1996-02-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"9\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Proceedings of IEEE 9th Annual Conference on Structure in Complexity Theory\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1109/SCT.1994.315809\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of IEEE 9th Annual Conference on Structure in Complexity Theory","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/SCT.1994.315809","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
M. Blum and R. Impagliazzo (Proc. 28th IEEE Symposium on Foundations of Computer Science, pp. 118-126, 1987), using techniques of Hartmanis and Hemachandra (1991) and Rackoff (1982), showed that if P = NP then P(G) = NP(G)/spl cap/co-NP(G) = UP(G), where G is a generic oracle. They left open the question as to whether these collapses occur at higher levels of the polynomial-time hierarchy. We give a surprising negative answer to this question. We show that relative to any generic oracle G and for any k/spl ges/ 2, there exists a tally set in U/spl Deltasub ksup P/(G)/spl capspl Pisub ksup P/(G) but not in /spl Deltasub ksup P/(G). An immediate corollary is that generic oracles separate /spl Sigmasub ksup Pspl capspl Pisub ksup P/ and /spl Deltasub ksup P/. We also show that related results hold for type-2 complexity.<>