Dice Question Streamline Icon: https://streamlinehq.com

Expected dimension for non-increasing width profiles

Establish that for any non-increasing width vector d=(d0,d1,…,dL) with output width dL>1 and any activation degree r∈N, the neurovariety V_{d,r} attains its expected dimension.

Information Square Streamline Icon: https://streamlinehq.com

Background

Beyond the asymptotic conjecture for large activation degree, the authors propose a structural conjecture that non-increasing width profiles (with dL>1) should be non-defective for every activation degree. They report empirical verification for small architectures using a backpropagation-based Jacobian rank routine, but no general proof is known.

This conjecture, if true, would give a broad family of deep architectures whose expressivity (as measured by dimension) matches the expected count derived from parameter symmetries.

References

In contrast to the asymptotic statement for large activation degree in Conjecture \ref{conj:asympEDim}, we also conjecture the following. Let $d=(d_0,d_1,\dots,d_L)$ be a non-increasing sequence with $d_L > 1$. Then for any $r$, the neurovariety $V_{d,r}$ attains the expected dimension.

Geometry of Polynomial Neural Networks (2402.00949 - Kubjas et al., 1 Feb 2024) in Section 5.1 (A plethora of conjectures)