Critical behaviour of combinatorial search algorithms, and the unitary-propagation universality class

Christophe Deroulers; Rémi Monasson

doi:10.1209/epl/i2004-10177-6

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Critical behaviour of combinatorial search algorithms, and the unitary-propagation universality class

Christophe Deroulers·Rémi Monasson

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Abstract

The probability P(alpha, N) that search algorithms for random Satisfiability problems successfully find a solution is studied as a function of the ratio alpha of constraints per variable and the number N of variables. P is shown to be finite if alpha lies below an algorithm--dependent threshold alpha\_A, and exponentially small in N above. The critical behaviour is universal for all algorithms based on the widely-used unitary propagation rule: P[ (1 + epsilon) alpha\_A, N] ~ exp[-N^(1/6) Phi(epsilon N^(1/3)) ]. Exponents are related to the critical behaviour of random graphs, and the scaling function Phi is exactly calculated through a mapping onto a diffusion-and-death problem.

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Christophe Deroulers, Rémi Monasson. 2006-03-20. Critical behaviour of combinatorial search algorithms, and the unitary-propagation universality class. https://doi.org/10.1209/epl%2Fi2004-10177-6

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