where <math>\beta</math> is the Lévy exponent.</ref>I. Pavlyukevich, Lévy flights, non-local search and simulated annealing, J. Computational Physics, Vol. 226, 1830-1844 (2007).</ref> It may be challenging to draw Lévy steps properly, and a simple way of generating Lévy flights <math>s</math> is to use two normal distributions <math>u</math> and <math>v</math> by a transform<ref>X. S. Yang, Nature-Inspired Optimization Algorithms, Elsevier, (2014).</ref>
