Graph-based collaborative filtering is capable of capturing the essential and
abundant collaborative signals from the high-order interactions, and thus
received increasingly research interests. Conventionally, the embeddings of
users and items are defined in the Euclidean spaces, along with the propagation
on the interaction graphs. Meanwhile, recent works point out that the
high-order interactions naturally form up the tree-likeness structures, which
the hyperbolic models thrive on. However, the interaction graphs inherently
exhibit the hybrid and nested geometric characteristics, while the existing
single geometry-based models are inadequate to fully capture such sophisticated
topological patterns. In this paper, we propose to model the user-item
interactions in a hybrid geometric space, in which the merits of Euclidean and
hyperbolic spaces are simultaneously enjoyed to learn expressive
representations. Experimental results on public datasets validate the
effectiveness of our proposal