A Wasserstein norm for signed measures, with application to non local transport equation with source term

We introduce the optimal transportation interpretation of the Kantorovich norm on the space of signed Radon measures with finite mass, based on a generalized Wasserstein distance for measures with different masses. With the formulation and the new topological properties we obtain for this norm, we prove existence and uniqueness for solutions to non-local and non-linear transport equations with source terms, when the initial condition is a signed measure.