In this paper, a sufficient condition for the existence of bifurcation points for discrete dynamical systems is presented. The relation between two families of systems is further discussed, and a sufficient condition for determining whether they may have the similar bifurcation points is given.
Let Aut*(X) denote the group of homotopy classes of self-homotopy equivalences of X, which induce identity automorphisms of homology group. We describe a decomposition of Aut*(X1∨…∨Xn) as a product of its simpler subgroups. We consider the subgroup AutΣ (X) of all self homotopy classes α of X such that Σα = 1ΣX : ΣX→ΣX, and also give some properties of AutΣ (X).
In this paper,we discuss the invariant measures for planar piecewise isometries.It is shown that the Hausdorff measure restricted to an almost invariant set with respect to the Hausdorff measure is invariant.
In this paper,we study the dynamical behaviour of an epidemic on complex networks with population mobility.In our model,the number of people on each node is unrestricted as the nodes of the network are considered as cities,communities,and so on.Because people can travel between different cities,we study the effect of a population'smobility on the epidemic spreading.In view of the population's mobility,we suppose that the susceptible individualcan be infected by an infected individual in the same city or other connected cities.Simulations are presented to verifyour analysis.
