# Simulated annealing

### From Glossary

An algorithm for solving hard problems, notably combinatorial programs, based on the metaphor of how annealing works: *reach a minimum energy state upon cooling a substance, but not too quickly in order to avoid reaching an undesirable final state*. As a heuristic search, it allows a non-improving move to a neighbor with a probability that decreases over time. The rate of this decrease is determined by the *cooling schedule*, often just a parameter used in an exponential decay (in keeping with the thermodynamic metaphor). With some (mild) assumptions about the cooling schedule, this will converge in probability to a global optimum.