[1991] Proceedings of the Sixth Annual Structure in Complexity Theory Conference

June 30 1991-July 3 1991

Filter Results

Displaying Results 1 - 25 of 39
  • Proceedings of the Sixth Annual Structure in Complexity Theory Conference (Cat. No.91CH3022-1)

    Publication Year: 1991
    Request permission for commercial reuse | PDF file iconPDF (689 KB)
    Freely Available from IEEE
  • BPP has subexponential time simulations unless EXPTIME has publishable proofs

    Publication Year: 1991, Page(s):213 - 219
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    It is shown that BPP can be simulated in subexponential time for infinitely many input lengths unless exponential time collapses to the second level of the polynomial-time hierarchy, has polynomial-size circuits, and has publishable proofs (EXPTIME=MA). It is also shown that BPP is contained in subexponential time unless exponential time has publishable proofs for infinitely many input lengths. In... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Notions of resource-bounded category and genericity

    Publication Year: 1991, Page(s):196 - 212
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1124 KB)

    The author investigates the strength of resource-bounded generic sets for deciding results in relativized complexity. He makes technical improvements to J.H. Lutz's notion of resource-bounded Baire category (1987, 1989) to show that almost every exponential-time set (in the author's sense of category) separate P from NP. It is shown that the author's improved notion of category, while strictly mor... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Combinatorics and Kolmogorov complexity

    Publication Year: 1991, Page(s):154 - 163
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (636 KB)

    The authors investigate combinatorial properties of finite sequences with high Kolmogorov complexity. They also demonstrate the utility of a Kolmogorov complexity method in combinatorial theory by several examples (such as the coin-weighing problem) View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Geometric arguments yield better bounds for threshold circuits and distributed computing

    Publication Year: 1991, Page(s):314 - 321
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (416 KB)

    The computational power of two-party probabilistic communication protocols is investigated. This model generalizes the concepts of nondeterministic and conondeterministic communication protocols in a natural way. Applications of the technique are presented, and some open problems are stated View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A pseudorandom oracle characterization of BPP

    Publication Year: 1991, Page(s):190 - 195
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    It is known from work of C.H. Bennett and J. Gill (1981) and K. Ambos-Spies (1986) that the following conditions are equivalent: (i) L∈BPP; (ii); for almost all oracles A, l∈PA. It is shown here that the following conditions are also equivalent to (i) and (ii): (iii) the set of oracles A for which L∈PA has pspace-mea... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the random-self-reducibility of complete sets

    Publication Year: 1991, Page(s):124 - 132
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (620 KB)

    Informally, a function f is random-self-reducible if the evaluation of f at any given instance x can be reduced in polynomial time to the evaluation of f at one or more random instances yi. A set is random-self-reducible if its characteristic function is. The authors generalize the previous formal definitions of random-self-reducibility. They... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On one query, self-reducible sets

    Publication Year: 1991, Page(s):139 - 151
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (876 KB)

    The authors study one-word-decreasing self-reducible sets, which are the usual self-reducible sets with the peculiarity that the self-reducibility machine makes at most one query to a word lexicographically smaller than the input. It is first shown that for all counting classes defined by a predicate on the number of accepting paths there exist complete sets which are one-word-decreasing self-redu... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Superlinear lower bounds for bounded-width branching programs

    Publication Year: 1991, Page(s):305 - 313
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (544 KB)

    The authors use algebraic techniques to obtain superlinear lower bounds on the size of bounded-width branching programs to solve a number of problems. In particular, they show that any bounded-width branching program computing a nonconstant threshold function has length Ω( n log log n), improving on the previous lower bounds known to apply to all such threshold functions. T... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Monotone separation of logspace from NC1

    Publication Year: 1991, Page(s):294 - 298
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    It is shown that the monotone analog of logspace computation is more powerful than monotone log-depth circuits: monotone circuits for a certain function in monotone logspace require depth Ω(lg2 n). It is proved that mNC1≠mL . This result shows that the process of pointer jumping, i.e. following a chain of pointers to the end, cannot be simu... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Counting auxiliary pushdown automata and semi-unbounded arithmetic circuits

    Publication Year: 1991, Page(s):270 - 284
    Cited by:  Papers (25)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (904 KB)

    The author examines various counting measures on space bounded nondeterministic auxiliary pushdown machines. In the main theorem, it is shown how a NAuxPDA may be simulated efficiently by a uniform family of Boolean circuits, which preserve the number of accepting paths in the NAuxPDA as the number of accepting subtrees in the Boolean circuit. The techniques used simulate the NAuxPDA in a novel wa... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Approximation and small depth Frege proofs

    Publication Year: 1991, Page(s):367 - 381
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (908 KB)

    M. Ajtai (1988) recently proved that if, for some fixed d, every formula in a Frege proof of the propositional pigeonhole principle PHPn has depth at most d, then the proof size is not less than any polynomial in n. By introducing the notion of an approximate proof the authors demonstrate how to eliminate the nonstandard model theory, including the nonconstruc... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Adaptive logspace and depth-bounded reducibilities

    Publication Year: 1991, Page(s):240 - 254
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1116 KB)

    The author discusses a number of results regarding the study of the computational power of depth-bounded reducibilities, their use to classify the complexity of computational problems, and their characterizations in terms of other computational models. In particular, problems arising in the design of concurrent systems are studied, and two kinds of logarithmic space reductions are defined. The fir... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the Monte Carlo Boolean decision tree complexity of read-once formulae

    Publication Year: 1991, Page(s):180 - 187
    Cited by:  Papers (7)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (504 KB)

    In the Boolean decision tree model there is at least a linear gap between the Monte Carlo and the Las Vegas complexity of a function depending on the error probability. The author proves for a large class of read-once formulae that this trivial speed-up is the best that a Monte Carlo algorithm can achieve. For every formula F belonging to that class it is shown that the Monte Carlo comple... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Capturing complexity classes by fragments of second order logic

    Publication Year: 1991, Page(s):341 - 352
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (780 KB)

    The expressive power of certain fragments of second-order logic on finite structures is investigated. The fragments are second-order Horn logic, second-order Krom logic, and a symmetric and a deterministic version of the latter. It is shown that all these logics collapse to their existential fragments. In the presence of a successor relation they provide characterizations of polynomial time, deter... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • PP is closed under truth-table reductions

    Publication Year: 1991, Page(s):13 - 15
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (156 KB)

    R. Beigel et al. (1991) showed that PP is closed under intersection and a variety of special cases of truth-table closure. In the present work, the authors extend the techniques of Beigel et al. to show that PP is closed under general polynomial-time truth-time reductions View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The power of witness reduction

    Publication Year: 1991, Page(s):43 - 59
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1012 KB)

    Recent results by M. Ogiwara and L.A. Hemachandra (1990) established a connection between functions being hard for a class of functions and functions interacting with the class to effect witness reduction. The author believes that the ability to achieve some form of witness reduction is what makes a function hard for a class of functions. To support this thesis he defines new function classes and ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the success probability of the two provers in one-round proof systems

    Publication Year: 1991, Page(s):116 - 123
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (568 KB)

    The author addresses the problem of reducing the error probability of two-prover one-round proof systems, without increasing the number of provers or the number of rounds. An example, the noninteractive agreement protocol, where executing such a protocol twice in parallel does not decrease the error probability at all is constructed. Upper bounds on the error probability of specific classes of pro... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Relating equivalence and reducibility to sparse sets

    Publication Year: 1991, Page(s):220 - 229
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (668 KB)

    For various polynomial-time reducibilities r, the authors ask whether being r-reducible to a sparse set is a broader notion than being r-equivalent to a sparse set. Although distinguishing equivalence and reducibility to sparse sets, for many-one or 1-truth-table reductions, would imply that P≠NP, the authors show that for k-truth-table reductions, <... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The complexity of malign ensembles

    Publication Year: 1991, Page(s):164 - 171
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (500 KB)

    The author analyzes the concept of malignness, which is the property of probability ensembles making the average case running time equal to the worst-case running time for a class of algorithms. He derives lower and upper bounds on the complexity of malign ensembles, which are tight for exponential time algorithms and which show that no polynomial time computable malign ensemble exists for the cla... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Lower bounds with smaller domain size on concurrent write parallel machines

    Publication Year: 1991, Page(s):322 - 331
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (784 KB)

    The author proves an optimum lower bound, separating the PRIORITY and the COMMON PRAM models on a much more reasonably sized input domain than that shown by R.B. Boppana (1989). The proposed techniques provide a greater understanding of the partial information a processor learns about the input. For example, the author defines a new measure of the dependency that a function has on a variable and d... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Bounded queries in recursion theory: a survey

    Publication Year: 1991, Page(s):62 - 78
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (864 KB)

    The author surveys much of the work that has been done on the following two questions: (1) What functions can one compute with m queries to A? and (2) Are there functions that can be computed with m queries to A that cannot be computed with m-1 queries to A? To any set X? The framework is recursion-theoretic; the computations have no ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • One-way functions, hard on average problems, and statistical zero-knowledge proofs

    Publication Year: 1991, Page(s):133 - 138
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (432 KB)

    The author studies connections among one-way functions, hard on the average problems, and statistical zero-knowledge proofs. In particular, he shows how these three notions are related and how the third notion can be better characterized, assuming the first one View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Super-logarithmic depth lower bounds via direct sum in communication complexity

    Publication Year: 1991, Page(s):299 - 304
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB)

    The question of whether it is easier to solve two communication problems together rather than separately is related to the complexity of the composition of Boolean functions. Based on this relationship, an approach to separating NC1 from P is outlined. Furthermore, it is shown that the approach provides a new proof of the separation of monotone NC1 ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The perceptron strikes back

    Publication Year: 1991, Page(s):286 - 291
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (404 KB)

    It is shown that every AC0 predicate is computed by a low-degree probabilistic polynomial over the reals. It is demonstrated that circuits composed of a symmetric gate at the root with AND-OR subcircuits of constant depth can be simulated by probabilistic depth-2 circuits with essentially the same symmetric gate at the root and AND gates of small fanin at the bottom. In particular, ever... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.