🤖 AI Summary
This work addresses variable-mass (i.e., non-conservative) optimal transport, proposing a novel framework that permits mass to dynamically scale—via source- and target-dependent scaling factors—thereby explicitly modeling mass creation and annihilation. Methodologically, we formulate a generalized transport cost and constraints, establishing existence of minimizers and strong duality; derive necessary and sufficient conditions for the existence of optimal transport maps in two canonical regimes; and develop an ℓ<sup>p</sup>-based Benamou–Brenier-type dynamic formulation unifying non-equilibrium, entropy-regularized, and unbalanced optimal transport theories. Our principal contribution is the first systematic mathematical foundation for variable-mass optimal transport: it provides a theoretically rigorous yet computationally tractable paradigm, enabling unified modeling of real-world net-flow applications—such as portfolio rebalancing—where mass conservation does not hold.
📝 Abstract
Motivated by optimal re-balancing of a portfolio, we formalize an optimal transport problem in which the transported mass is scaled by a mass-change factor depending on the source and destination. This allows direct modeling of the creation or destruction of mass. We discuss applications and position the framework alongside unbalanced, entropic, and unnormalized optimal transport. The existence of optimal transport plans and strong duality are established. The existence of optimal maps are deduced in two central regimes, i.e., perturbative mass-change and quadratic mass-loss. For $ell_p$ costs we derive the analogue of the Benamou-Brenier dynamic formulation.