Mass conservation and gelation for the Smoluchowski coagulation equation: a generalized moment approach

The Smoluchowski coagulation equation (SCE) is a population balance model that describes the time evolution of cluster size distributions resulting from particle aggregation. Although it is formally a mass-conserving system, solutions may exhibit a gelation phenomenon–a sudden loss of mass–when the coagulation kernel grows superlinearly. In this paper, we rigorously analyze mass conservation and gelation for weak solutions to the SCE with inhomogeneous coagulation kernels. By introducing a generalized moment framework, we derive sufficient conditions for both mass conservation and gelation, expressed in terms of the initial data and the properties of the coagulation kernel.