A generalization of resource-bounded measure, with application to the BPP vs. EXP problem

Citation
H. Buhrman et al., A generalization of resource-bounded measure, with application to the BPP vs. EXP problem, SIAM J COMP, 30(2), 2000, pp. 576-601
Citations number
33
Categorie Soggetti
Computer Science & Engineering
Journal title
SIAM JOURNAL ON COMPUTING
ISSN journal
00975397 → ACNP
Volume
30
Issue
2
Year of publication
2000
Pages
576 - 601
Database
ISI
SICI code
0097-5397(20000628)30:2<576:AGORMW>2.0.ZU;2-K
Abstract
We introduce resource-bounded betting games and propose a generalization of Lutz's resource-bounded measure in which the choice of the next string to bet on is fully adaptive. Lutz's martingales are equivalent to betting game s constrained to bet on strings in lexicographic order. We show that if str ong pseudorandom number generators exist, then betting games are equivalent to martingales for measure on E and EXP. However, we construct betting gam es that succeed on certain classes whose Lutz measures are important open p roblems: the class of polynomial-time Turing-complete languages in EXP and its superclass of polynomial-time Turing-autoreducible languages. If an EXP -martingale succeeds on either of these classes, or if betting games have t he "finite union property" possessed by Lutz's measure, one obtains the non relativizable consequence BPP not equal EXP. We also show that if EXP not e qual MA, then the polynomial-time truth-table-autoreducible languages have Lutz measure zero, whereas if EXP = BPP, they have measure one.