Relate diffeomorphism sensitivity to hierarchical representation formation

Establish how the empirically observed correlation between a network’s test error and its sensitivity to diffeomorphisms relates to the formation of hierarchical representations in deep neural networks trained on high-dimensional visual data, clarifying the mechanisms that connect deformation stability and hierarchical feature abstraction.

Background

The paper highlights a strong empirical correlation: networks with lower sensitivity to diffeomorphisms tend to achieve better test performance. Despite this observation, prior work did not explain how deformation stability connects to the emergence of hierarchical representations, a hallmark of deep networks.

The authors introduce the Sparse Random Hierarchy Model to unify these viewpoints, but the introduction frames the general relationship as unexplained at the time. Providing a comprehensive theoretical account that directly links diffeomorphism stability and hierarchical representation learning beyond the specific model would address this broader uncertainty.

References

Currently, these observations remain unexplained, and it is not clear how they relate with the fact that neural networks build a hierarchical representations of data.

How Deep Networks Learn Sparse and Hierarchical Data: the Sparse Random Hierarchy Model (2404.10727 - Tomasini et al., 16 Apr 2024) in Section 1, Introduction