A Computational Approach to Polynomial Conservation Laws

TL;DR

This paper introduces algorithmic methods for computing and analyzing polynomial conservation laws in ODE models, aiding model reduction and multistationarity studies, especially in chemical reaction networks.

Contribution

It presents new algorithms for finding and testing the completeness of polynomial conservation laws, including a novel approach using comprehensive Gr"obner systems and syzygies.

Findings

Algorithms for linear, monomial, and polynomial conservation laws

Method to test the completeness of conservation laws

Parametric analysis of conservation laws' dependence on parameters

Abstract

For polynomial ODE models, we introduce and discuss the concepts of exact and approximate conservation laws, which are the first integrals of the full and truncated sets of ODEs. For fast-slow systems, truncated ODEs describe the fast dynamics. We define compatibility classes as subsets of the state space, obtained by equating the conservation laws to constants. A set of conservation laws is complete when the corresponding compatibility classes contain a finite number of steady states. Complete sets of conservation laws can be used for model order reduction and for studying the multistationarity of the model. We provide algorithmic methods for computing linear, monomial, and polynomial conservation laws of polynomial ODE models and for testing their completeness. The resulting conservation laws and their completeness are either independent or dependent on the parameters. In the latter case, we provide parametric case distinctions. In particular, we propose a new method to compute polynomial conservation laws by comprehensive Gr\"obner systems and syzygies. Keywords: First integrals, chemical reaction networks, polynomial conservation laws, syzygies, comprehensive Gr\"obner systems.