Collapsed Effective Operators for Higher-order Structures
This provides a unified framework for practitioners working with higher-order structures, eliminating ad hoc fusion of spectral information across ranks.
The paper introduces Collapsed Effective Operators, which condense higher-order topological information into a single vertex-level operator via Schur complementation, enabling improved spectral clustering, signal smoothing, and integration into neural networks.
Higher-order structures are powerful relational modeling tools, yet existing spectral operators decompose the topology into separate ranks, leaving practitioners to fuse the information back to vertices through ad hoc choices. We introduce Collapsed Effective Operators, which condense higher-order degrees of freedom into a single vertex-level operator via Schur complementation of a graded Laplacian. This yields a (generally dense) operator that encodes long-range interactions mediated by topology and is applicable to arbitrary higher-order constructs. We show it preserves positive semi-definiteness with a spectral upper bound relative to the rank-0 Hodge Laplacian, effectively lowering system energy under higher-order connectivity. Empirically, our operator improves spectral clustering, signal smoothing, and enables the inclusion of topological features in neural network architectures via positional encoding. The project page can be found http://circle-group.github.io/research/CollapsedEffectiveOperators