Characteristic Imsets for Cyclic Linear Causal Models and the Chickering Ideal
循环线性因果模型的特征 imset 与 Chickering 理想
Two directed graphs are called covariance equivalent if they induce the same set of covariance matrices, up to a Lebesgue measure zero set, on the random variables of their associated linear structural equation models. For acyclic graphs, covariance equivalence is characterized both structurally, via essential graphs and characteristic imsets, and transformationally, through sequences of covered edge flips. However, when cycles are allowed, only a transformational…