title: Center of mass in complex networks.
abstract: Network dynamics is always a big challenge in nonlinear dynamics. Although great advancements have been made in various types of complex systems, an universal theoretical framework is required. In this paper, we introduce the concept of center of 'mass' of complex networks, where 'mass' stands for node importance or centrality in contrast to that of particle systems, and further prove that the phase transition and evolutionary state of the system can be characterized by the activity of center of 'mass'. The steady states of several complex networks (gene regulatory networks and epidemic spreading systems) are then studied by analytically calculating the decoupled equation of the dynamic activity of center of 'mass', which is derived from the dynamic equation of the complex networks. The limitations of this method are also pointed out, such as the dynamical problems that related with the relative activities among components, and those systems that consist of oscillatory or chaotic motions.
authors.affiliation: School of Physical Electronics, University of Electronic Science and Technology of China, Cheng Du 610054, P.R. China.
authors.forename: Chuanji
authors.initials: C
authors.lastname: Fu
authors.affiliation: School of Physical Electronics, University of Electronic Science and Technology of China, Cheng Du 610054, P.R. China.
authors.forename: Yachun
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Web Sciences Center &Big Data Research Center, University of Electronic Science and Technology of China, Cheng Du 610054, P.R. China.
authors.forename: Shimin
authors.initials: S
authors.lastname: Cai
authors.affiliation: School of Physical Electronics, University of Electronic Science and Technology of China, Cheng Du 610054, P.R. China.
authors.forename: Hongchun
authors.initials: H
authors.lastname: Yang
authors.affiliation: School of Mathematical Science, University of Electronic Science and Technology of China, Cheng Du 610054, P.R. China.
authors.forename: Chun
authors.initials: C
authors.lastname: Yang