Global existence and boundedness for a degenerate chemotaxis system with indirect signal production via minimizing movement schemes

Global existence and boundedness of weak solutions for a fully parabolic degenerate chemotaxis system with indirect signal production are proved for any initial data in the subcritical case and under smallness conditions in the critical and supercritical cases.

To construct weak solutions, a time discrete scheme is set up, for which the first equation has a gradient flow structure with respect to the 2-Wasserstein distance, while the other two equations feature an L\textsuperscript{2}-variational structure.

The proof relies in particular on the flow interchange method and discrete maximal regularity.