On stability in probability for a cooperative system of two equations with Nicholson’s growth and distributed delay under stochastic perturbations

A method of stability investigation for stochastic nonlinear dynamical systems is demonstrated on a system of two connected Nicholson’s blowflies type equations with distributed delay and exponential nonlinearity. It is supposed that this system is affected by stochastic perturbations of the white noise type that are directly proportional to the deviation of the system state from its equilibrium. Stability conditions for the zero and positive equilibria of the system under consideration are obtained by virtue of the general method of Lyapunov functionals construction and are formulated in terms of Linear Matrix Inequalities (LMIs), that can be checked by MATLAB. Numerical examples and figures illustrate the obtained theoretical results. The described method can be applied in various applications to many stochastic systems of higher dimensions with different types of high-order nonlinearities and different forms of delays.