English

Solving satisfiability problems by fluctuations: The dynamics of stochastic local search algorithms

Statistical Mechanics 2009-11-10 v2 Disordered Systems and Neural Networks Computational Complexity

Abstract

Stochastic local search algorithms are frequently used to numerically solve hard combinatorial optimization or decision problems. We give numerical and approximate analytical descriptions of the dynamics of such algorithms applied to random satisfiability problems. We find two different dynamical regimes, depending on the number of constraints per variable: For low constraintness, the problems are solved efficiently, i.e. in linear time. For higher constraintness, the solution times become exponential. We observe that the dynamical behavior is characterized by a fast equilibration and fluctuations around this equilibrium. If the algorithm runs long enough, an exponentially rare fluctuation towards a solution appears.

Keywords

Cite

@article{arxiv.cond-mat/0301271,
  title  = {Solving satisfiability problems by fluctuations: The dynamics of stochastic local search algorithms},
  author = {Wolfgang Barthel and Alexander K. Hartmann and Martin Weigt},
  journal= {arXiv preprint arXiv:cond-mat/0301271},
  year   = {2009}
}

Comments

21 pages, 18 figures, revised version, to app. in PRE (2003)