Hessian eigenvalue plots show removing activation bias flattens the loss landscape

ZimingLiu11 · x · 2026-10-31

Part 6/N of the same research thread: experiments plotting Hessian eigenvalues at training steps 0/5000/10000 show that removing the activation bias cuts top eigenvalues from 20-50 down to 2, flattening the loss landscape throughout training.

This explains why optimization no longer suffers from sharp "valley" directions that cause oscillations and loss spikes. An auto-encoder experiment additionally shows the representation's monotonic evolution is restored once the bias is removed.

Related event: Ziming Liu: Popular activations have non-zero mean; negative shift stabilizes training(8 posts)→

Original post →

More from Research

Research channel →