Towards Understanding Neural Collapse: The Effects of Batch Normalization and Weight Decay
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Abstract (arXiv)
Neural Collapse (NC) is a geometric structure recently observed at the terminal phase of training deep neural networks, which states that last-layer feature vectors for the same class would "collapse" to a single point, while features of different classes become equally separated. We demonstrate that batch normalization (BN) and weight decay (WD) critically influence the emergence of NC. In the near-optimal loss regime, we establish an asymptotic lower bound on the emergence of NC that depends only on the WD value, training loss, and the presence of last-layer BN. Our experiments substantiate theoretical insights by showing that models demonstrate a stronger presence of NC with BN, appropriate WD values, lower loss, and lower last-layer feature norm. Our findings offer a novel perspective in studying the role of BN and WD in shaping neural network features.
Key facts. Cited by 9 papers in the map (data through 7 Oct 2026). Builds on 29 of its 58 references that are in the map. First posted on arXiv 9 Sep 2023.
Builds on
29 of 58 references.
References · 29
- 2015Deep Residual Learning for Image Recognitioncited by 51,809
- 2019PyTorch: An Imperative Style, High-Performance Deep Learning Librarycited by 20,160
- 2014Very Deep Convolutional Networks for Large-Scale Image Recognitioncited by 15,267
- 2015Batch Normalization: Accelerating Deep Network Training by Reducing Internal Covariate Shiftcited by 6,979
- 2020Prevalence of Neural Collapse during the terminal phase of deep learning trainingcited by 713
- 2018How Does Batch Normalization Help Optimization?cited by 355
- 2021A Geometric Analysis of Neural Collapse with Unconstrained Featurescited by 226
- 2018Understanding Batch Normalizationcited by 157
- 2021Neural Collapse Under MSE Loss: Proximity to and Dynamics on the Central Pathcited by 156
- 2020Neural collapse with unconstrained featurescited by 140
- 2017L2 Regularization versus Batch and Weight Normalizationcited by 121
- 2022Extended Unconstrained Features Model for Exploring Deep Neural Collapsecited by 101
17 more
- 2021On the Role of Neural Collapse in Transfer Learningcited by 100
- 2022On the Optimization Landscape of Neural Collapse under MSE Loss: Global Optimality with Unconstrained Featurescited by 97
- 2022Neural Collapse: A Review on Modelling Principles and Generalizationcited by 95
- 2021An Unconstrained Layer-Peeled Perspective on Neural Collapsecited by 87
- 2020Why Do Better Loss Functions Lead to Less Transferable Features?cited by 73
- 2020Reconciling Modern Deep Learning with Traditional Optimization Analyses: The Intrinsic Learning Ratecited by 59
- 2019A Mean Field Theory of Batch Normalizationcited by 58
- 2018Towards Understanding Regularization in Batch Normalizationcited by 56
- 2020On the emergence of simplex symmetry in the final and penultimate layers of neural network classifierscited by 51
- 2022Neural Collapse with Normalized Features: A Geometric Analysis over the Riemannian Manifoldcited by 50
- 2023Deep Neural Collapse Is Provably Optimal for the Deep Unconstrained Features Modelcited by 43
- 2020Explicit regularization and implicit bias in deep network classifiers trained with the square losscited by 37
- 2018Exponential convergence rates for Batch Normalization: The power of length-direction decoupling in non-convex optimizationcited by 27
- 2022Nearest Class-Center Simplification through Intermediate Layerscited by 20
- 2022On the Implicit Bias Towards Minimal Depth of Deep Neural Networkscited by 12
- 2022Batch Normalization Explainedcited by 8
- 2015On the Importance of Normalisation Layers in Deep Learning with Piecewise Linear Activation Unitscited by 6
Built on by
Citing papers per year: 2024: 3; 2025: 3; 2026: 3.
9 papers.
- 2024Neural Collapse versus Low-rank Bias: Is Deep Neural Collapse Really Optimal?cited by 16
- 2024Wide Neural Networks Trained with Weight Decay Provably Exhibit Neural Collapsecited by 14
- 2025Cautious Weight Decaycited by 12
- 2025Controlling Neural Collapse Enhances Out-of-Distribution Detection and Transfer Learningcited by 11
- 2024The Fair Language Model Paradoxcited by 3
- 2026Neural Collapse Dynamics: Depth, Activation, Regularisation, and Feature Norm Thresholdcited by 2
- 2026Optimizer choice matters for the emergence of Neural Collapsecited by 1
- 2026Deep Neural Regression Collapsecited by 1
- 2025TRUST: Test-time Resource Utilization for Superior Trustworthinesscited by 0
- 2026Neural Collapse Dynamics: Depth, Activation, Regularisation, and Feature Norm Threshold31 Mar 2026
- 2026Deep Neural Regression Collapse25 Mar 2026
- 2026Optimizer choice matters for the emergence of Neural Collapse18 Feb 2026
- 2025Cautious Weight Decay14 Oct 2025
- 2025TRUST: Test-time Resource Utilization for Superior Trustworthiness6 Jun 2025
- 2025Controlling Neural Collapse Enhances Out-of-Distribution Detection and Transfer Learning15 Feb 2025
- 2024The Fair Language Model Paradox15 Oct 2024
- 2024Wide Neural Networks Trained with Weight Decay Provably Exhibit Neural Collapse7 Oct 2024
- 2024Neural Collapse versus Low-rank Bias: Is Deep Neural Collapse Really Optimal?23 May 2024