| Siphons in a chemical reaction system are subsets of the species that have the potential of being absent in a steady state. This talk presents a characterization of minimal siphons in terms of primary decomposition of binomial ideals, explores the underlying geometry, and demonstrates the effective computation of siphons using computer algebra software. This leads to a new method for determining whether given initial concentrations allow for various boundary steady states; this classification arises from the combinatorics of a chamber decomposition. This is joint work with Bernd Sturmfels. |