ACR-preserving networks

Absolute concentration robustness in networks with many conservation laws

We show that for many simple networks, absolute concentration robustness (acr) can be assessed by simply inspecting a network or its standard embedding into euclidean space.Our main results pertain to networks with many conservation laws, so that all reactions are parallel to oneother.Such"one-dimensional"networks include those networks having only one species.We also consider networks with only two reactions, and show that acr is characterized by a well-known criterion of shinar and feinberg.Finally, up to some natural acr-preserving operations (relabeling species, lengthening a reaction, and so on), only three families of networks with two reactions and two species have acr.