Abstract:
We use the subordination principle together with an equivalent norm approach and semigroup
perturbation theory to state and set conditions for a non-autonomous fragmentation system to
be conservative. The model is generalized with the Caputo fractional order derivative and we
assume that the renormalizable generators involved in the perturbation process are in the class of
quasi-contractive semigroups, but not in the class G(1; 0) as usually assumed. This, thenceforth,
allows the use of admissibility with respect to the involved operators, Hermitian conjugate, Hille-
Yosida's condition and the uniform boundedness to show that the operator sum is closable, its
closure generates a propagator (evolution system) and, therefore, a C0 semigroup, leading to the
existence result and conservativeness of the fractional model. This work brings a contribution
that may lead to the full characterization of the in nitesimal generator of a C0 semigroup for
fractional non-autonomous fragmentation and coagulation dynamics which remain unsolved.
