# Tensor Programs IVb: Adaptive Optimization in the Infinite-Width Limit

arXiv: https://arxiv.org/abs/2308.01814 · HTML: https://mlsanity.com/paper/2308.01814/

## Key facts

- Cited by 38 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 3 Aug 2023.

## Built on by (most cited first, 30 of 38)

- [LoRA+: Efficient Low Rank Adaptation of Large Models](https://mlsanity.com/paper/2402.12354/) (2024)
- [Don't be lazy: CompleteP enables compute-efficient deep transformers](https://mlsanity.com/paper/2505.01618/) (2025)
- [Distillation Scaling Laws](https://mlsanity.com/paper/2502.08606/) (2025)
- [The Impact of Initialization on LoRA Finetuning Dynamics](https://mlsanity.com/paper/2406.08447/) (2024)
- [Scaling Laws for Associative Memories](https://mlsanity.com/paper/2310.02984/) (2023)
- [u-μP: The Unit-Scaled Maximal Update Parametrization](https://mlsanity.com/paper/2407.17465/) (2024)
- [There Will Be a Scientific Theory of Deep Learning](https://mlsanity.com/paper/2604.21691/) (2026)
- [Compute Better Spent: Replacing Dense Layers with Structured Matrices](https://mlsanity.com/paper/2406.06248/) (2024)
- [Completed Hyperparameter Transfer across Modules, Width, Depth, Batch and Duration](https://mlsanity.com/paper/2512.22382/) (2025)
- [Super Consistency of Neural Network Landscapes and Learning Rate Transfer](https://mlsanity.com/paper/2402.17457/) (2024)
- [Scaling Collapse Reveals Universal Dynamics in Compute-Optimally Trained Neural Networks](https://mlsanity.com/paper/2507.02119/) (2025)
- [Hyperparameter Transfer Enables Consistent Gains of Matrix-Preconditioned Optimizers Across Scales](https://mlsanity.com/paper/2512.05620/) (2025)
- [Leave-one-out Distinguishability in Machine Learning](https://mlsanity.com/paper/2309.17310/) (2023)
- [On the Parameterization of Second-Order Optimization Effective Towards the Infinite Width](https://mlsanity.com/paper/2312.12226/) (2023)
- [StelLA: Subspace Learning in Low-rank Adaptation using Stiefel Manifold](https://mlsanity.com/paper/2510.01938/) (2025)
- [Searching for Efficient Linear Layers over a Continuous Space of Structured Matrices](https://mlsanity.com/paper/2410.02117/) (2024)
- [The Optimization Landscape of SGD Across the Feature Learning Strength](https://mlsanity.com/paper/2410.04642/) (2024)
- [Deriving Hyperparameter Scaling Laws via Modern Optimization Theory](https://mlsanity.com/paper/2603.15958/) (2026)
- [Robust Layerwise Scaling Rules by Proper Weight Decay Tuning](https://mlsanity.com/paper/2510.15262/) (2025)
- [μLO: Compute-Efficient Meta-Generalization of Learned Optimizers](https://mlsanity.com/paper/2406.00153/) (2024)
- [Understanding the Mechanisms of Fast Hyperparameter Transfer](https://mlsanity.com/paper/2512.22768/) (2025)
- [Scaling Diffusion Transformers Efficiently via μP](https://mlsanity.com/paper/2505.15270/) (2025)
- [SOAP, Muon, and Beyond: Pushing LLM Pretraining Scales](https://mlsanity.com/paper/2607.20548/) (2026)
- [Infinite-Width Limit of a Single Attention Layer: Analysis via Tensor Programs](https://mlsanity.com/paper/2506.00846/) (2025)
- [Three Mechanisms of Feature Learning in a Linear Network](https://mlsanity.com/paper/2401.07085/) (2024)
- [Local Loss Optimization in the Infinite Width: Stable Parameterization of Predictive Coding Networks and Target Propagation](https://mlsanity.com/paper/2411.02001/) (2024)
- [Learnable Multipliers: Freeing the Scale of Language Model Matrix Layers](https://mlsanity.com/paper/2601.04890/) (2026)
- [On the Infinite Width and Depth Limits of Predictive Coding Networks](https://mlsanity.com/paper/2602.07697/) (2026)
- [Transforming Rank: How Architecture Navigates the Spectral Pathologies of Depth](https://mlsanity.com/paper/2607.14018/) (2026)
- [Towards Steering without Sacrifice: Principled Training of Steering Vectors for Prompt-only Interventions](https://mlsanity.com/paper/2605.05983/) (2026)

## Abstract (arXiv)

Going beyond stochastic gradient descent (SGD), what new phenomena emerge in wide neural networks trained by adaptive optimizers like Adam? Here we show: The same dichotomy between feature learning and kernel behaviors (as in SGD) holds for general optimizers as well, including Adam -- albeit with a nonlinear notion of "kernel." We derive the corresponding "neural tangent" and "maximal update" limits for any architecture. Two foundational advances underlie the above results: 1) A new Tensor Program language, NEXORT, that can express how adaptive optimizers process gradients into updates. 2) The introduction of bra-ket notation to drastically simplify expressions and calculations in Tensor Programs. This work summarizes and generalizes all previous results in the Tensor Programs series of papers.
