The large-scale organization of chemical reaction networks in astrophysics

Abstract

The large-scale organization of complex networks, both natural and\nartificial, has shown the existence of highly heterogeneous patterns of\norganization. Such patterns typically involve scale-free degree distributions\nand small world, modular architectures. One example is provided by chemical\nreaction networks, such as the metabolic pathways. The chemical reactions of\nthe Earth's atmosphere have also been shown to give rise to a scale-free\nnetwork. Here we present novel data analysis on the structure of several\nastrophysical networks including the chemistry of the planetary atmospheres and\nthe interstellar medium. Our work reveals that Earth's atmosphere displays a\nhierarchical organization, close to the one observed in cellular webs. Instead,\nthe other astrophysical reaction networks reveal a much simpler pattern\nconsistent with an equilibrium state. The implications for large-scale\nregulation of the planetary dynamics are outlined.\n