On the existence of positive periodic solutions to a Lotka Volterra cooperative population model with multiple delays

In this paper, the author studies the existence of positive periodic solutions to a Lotka Volterra cooperative population model with multiple delays as follows xi′(t)=xi(t)[ri(t)−pii(t)xi(t)+∑k≠inpik(t)xk(t)−∑j=1nqij(t)xi(t−τij(t))+∑k≠in∑j=1ncikj(t)xk(t−γikj(t))],(i=1,2,…,n). By using Mawhin’s continuation theorem of coincidence degree principle, a new result is obtained. The interesting thing is that the result is related to the delays, which is different from the corresponding ones of the known literature.