We can generalize representing different properties of time-varying signals beyond the chain graph by considering arbitrary adjacency matrices and Laplacians.

$Q_h = \alpha_0I + \alpha_1A + \alpha_2A^2 + ... + \alpha_nA^N$

Therefore, when we multiply a matrix of node features X $\in \mathbb{R}^{|v|*m}$, then we get

$Q_hX = \alpha_0IX + \alpha_1AX + \alpha_2A^2X + ... + \alpha_nA^NX$

where $Q_hX[u]$ at a given node $u$ corresponds to a vector $\in \mathbb{R}^m$ that contains information in the node's $N$-hop neighborhood.