The polydisperse coagulation equation
models irreversible aggregation of particles with varying masses. This paper uses a one-parameter family of discrete-time continuous multitype branching processes to solve the polydisperse coagulation equation when ![](//static-cambridge-org.ezproxyberklee.flo.org/content/id/urn%3Acambridge.org%3Aid%3Aarticle%3AS0001867800022345/resource/name/S0001867800022345_eqnU2.gif?pub-status=live)
The critical time tc when
diverges corresponds to a critical branching process, while post-critical times t> tc correspond to supercritical branching processes.