2026
Posterior Mismatch Matters: Adversarial Training for Long-Tailed Robustness
ICML 2026poster
Adversarial training breaks down in long-tailed settings, exhibiting severe robustness degradation on worst-performing (often tail) classes. We identify a key cause of this failure as a posterior mismatch: coarse-grained absolute labels collapse class posteriors into point estimates, leading to bias…