Higher-order data

Perform inference on systems involving interactions between groups of nodes of any arbitrary size.

In recent years, real-world data from diverse domains, including social and biological systems, have revealed interactions that go beyond pairwise connections, involving groups of nodes of various sizes. Hypergraphs provide a versatile and comprehensive framework for characterizing systems where such higher-order interactions are relevant. To analyze such data, models must extend beyond conventional dyadic interactions (represented as \(A_{ij}\)) and instead focus on hyperedges, referred to as \(d\)-dimensional interactions \(A_e\), where \(d=\|e\|\).

We developed two distinct probabilistic models designed to perform inference on hypergraphs while capturing their hidden structural organization. These models, named Hypergraph-MT (Contisciani et al., 2022) and Hy-MMSBM (Ruggeri et al., 2023), posit the existence of a mixed-membership community structure as the main generative process, and utilize Poisson distributions to model the hyperedges. The main difference between the two approaches lies in how they integrate latent variables into the model, leading to two different assumptions about data generation.

Specifically, Hypergraph-MT describes a hyperedge through the product of the memberships of all nodes involved, assuming exclusively assortative community structures to make this computation feasible. On the other hand, Hy-MMSBM relaxes the assortativity constraint and flexibly captures various community structures, such as disassortative and core-periphery. It achieves this by employing a bilinear form to link hyperedge probabilities and node community memberships.

These models, along with a broad range of other tools and algorithms for handling data with higher-order interactions, are available in the Python library hypergraphx (Lotito et al., 2023).

Main takeaways

  • Our models reliably predict the existence of higher-order interactions of arbitrary size.
  • Hypergraph-MT detects communities that reliable depict the information carried by hyperedges and exhibit robustness against the addition of noisy interactions.
  • Hy-MMSBM accurately retrieves the planted communities in scenarios with varying hyperedges sizes, effectively captures assortative and disassortative community structures, and correctly represents core-periphery configurations.

References

  1. [6]
    Inference of hyperedges and overlapping communities in hypergraphs
    Martina Contisciani, Federico Battiston, and Caterina De Bacco
    Nature Communications, 2022
  2. [9]
    Community detection in large hypergraphs
    Nicolò Ruggeri, Martina Contisciani, Federico Battiston, and Caterina De Bacco
    Science Advances, 2023
  3. [8]
    Hypergraphx: a library for higher-order network analysis
    Quintino Francesco Lotito, Martina Contisciani, Caterina De Bacco, Leonardo Di Gaetano, Luca Gallo, Alberto Montresor, Federico Musciotto, Nicolò Ruggeri, and Federico Battiston
    Journal of Complex Networks, 2023