Pure Multiplicative Noises Induced Population Extinction in an Anti-tumor Model under Immune Surveillance

摘要

The dynamical characters of a theoretical anti-tumor model under immune surveillance subjected to a puremultiplicative noise are investigated.The effects of pure multiplicative noise on the stationary probability distribution(SPD) and the mean first passage time (MFPT) are analysed based on the approximate Fokker-Planck equation of thesystem in detail.For the anti-tumor model,with the multiplicative noise intensity D increasing,the tumor populationmove towards to extinction and the extinction rate can be enhanced.Numerical simulations are carried out to check theapproximate theoretical results.Reasonably good agreement is obtained.