Abstract boundary delay systems and application to network flow
András Bátkai, Marjeta Kramar Fijavž, Abdelaziz Rhandi
TL;DR
The paper addresses well posedness and positivity for delayed transport on networks modeled as metric graphs. It reformulates the problem as an abstract boundary delay equation and uses Staffans-Weiss perturbation to obtain a strongly continuous semigroup generated by $\mathcal{A}_{P,L}$, together with resolvent descriptions and positivity criteria. Spectral analysis introduces the condition $1\in\rho(\Delta(\lambda))$ that characterizes the spectrum, and positivity is established under positivity of the delay operators and suitable large parameter limits. The theory is then applied to a network flow with delays, proving well posedness and positivity and providing explicit state-trajectory representations. These results advance the mathematical understanding of delay effects in network transport and support applications to material flow in interconnected systems.
Abstract
This paper investigates the well-posedness and positivity of solutions to a class of delayed transport equations on a network. The material flow is delayed at the vertices and along the edges. The problem is reformulated as an abstract boundary delay equation, and well-posedness is proved by using the Staffans-Weiss theory. We also establish spectral theory for the associated delay operators and provide conditions for the positivity of the semigroup.
