$\mathcal{H}_2$ performance of series-parallel networks: A compositional perspective

We examine the $\mathcal{H}_2$ norm of matrix-weighted leader-follower consensus on series-parallel networks. By using an extension of electrical network theory on matrix-valued resistances, voltages and currents, we show that the computation of the $\mathcal{H}_2$ norm can be performed efficiently by decomposing the network into atomic elements and composition rules. Lastly, we examine the problem of efficiently adapting the matrix-valued edge weights to optimize the $\mathcal{H}_2$ norm of the network.