## Section: Research Program

### Chemical Reaction Network (CRN) Theory

Feinberg's chemical reaction network theory
and Thomas's influence network analyses
provide sufficient and/or necessary structural conditions for the existence of multiple steady states and oscillations
in regulatory networks.
Those conditions can be verified by static analyzers without knowing kinetic parameter values nor making any simulation.
In this domain, most of our work consists in analyzing the interplay between the **structure** (Petri net properties, influence graph, subgraph epimorphisms)
and the **dynamics** (Boolean, CTMC, ODE, time scale separations) of biochemical reaction systems.
In particular, our study of influence graphs of reaction systems,
our generalization of Thomas' conditions of multi-stationarity and Soulé's proof
to reaction systems (Sylvain Soliman. A stronger necessary condition for the multistationarity of chemical reaction networks. Bulletin of Mathematical Biology, 75(11):2289–2303, 2013.), the inference of reaction systems from ODEs (François Fages, Steven Gay, Sylvain Soliman. Inferring reaction systems from ordinary differential equations. Journal of Theoretical Computer Science (TCS), Elsevier, 2015, 599, pp.64–78.), the computation of structural invariants by constraint programming techniques,
and the analysis of model reductions by subgraph
epimorphisms now provide solid ground for developing static analyzers,
using them on a large scale in systems biology, and elucidating modules.