arXiv Machine Learning

MuPACE: Learning to Pace Muon for LoRA Fine-Tuning

arXiv Machine Learning
Jul 15

AMUSE: Anytime Muon with Stable Gradient Evaluation

arXiv:2605. 22432v2 Announce Type: replace Abstract: Modern deep learning commonly relies on AdamW with prescribed learning rate schedules, but recent works challenge both components: Schedule-Free optimization removes explicit schedules via iterate averaging, and Muon improves the update geometry by orthogonalizing momentum for matrix parameters.

By Jueun Kim, Baekrok Shin, Jihun Yun, Beomhan Baek, Minhak Song, Chulhee Yun
arXiv AI
Jun 12

LoRA-Muon: Spectral Steepest Descent on the Low-Rank Manifold

arXiv:2606. 12921v1 Announce Type: cross Abstract: Low-Rank Adaptation (LoRA) significantly reduces compute and memory costs for finetuning Deep Learning models but is often harder to tune than dense training: when using factor-wise optimizers such as AdamW, it is sensitive to initialization choices, its optimal learning rates transfer poorly across ranks, and it often fails to beat dense baselines.

By Franz Louis Cesista, Katherine Crowson, C\'edric Simal, Stella Biderman
arXiv Machine Learning
Sep 22

Muon Can Outperform Dedicated Continual Learning Methods

arXiv:2609.24678v1 Announce Type: new Abstract: Continual learning with Low-Rank Adapters (LoRA) typically mitigates forgetting by penalizing the overlap between a new update and the accumulated past...

By Sebastian George Sincari (Faculty of Mathematics and Computer Science, University of Bucharest, Bucharest, Romania), Bogdan Alexandru Gheorghe (Faculty of Mathematics and Computer Science, University of Bucharest, Bucharest, Romania), Antonio Barbalau (Bitdefender, Bucharest, Romania)
arXiv Machine Learning
6d ago

The Ephemeral Cost of Switching Optimizers Across LLM Training Stages

The study investigates whether switching optimizers between pretraining and subsequent training stages of large language models (LLMs) incurs a performance penalty. By pretraining 1.2B Llama‑3 models with varying proportions of AdamW and Muon updates, and interpolating between the two during continued pretraining and supervised fine‑tuning (SFT), the authors find little evidence of a meaningful optimizer mismatch penalty. The results show that final performance is largely determined by the independent effects of the pretraining and post‑training optimizers, with downstream performance generally improving as the proportion of Muon updates during SFT increases, and that Muon remains competitive with AdamW even for task‑general SFT on larger models.

By Xinyu Zhao, Davis Wertheimer, Ashutosh Sharma, Rameswar Panda, Paul Pu Liang
arXiv Machine Learning
Sep 29

New LoRA Skills Should Read but Never Write

The paper introduces READ, a method for composing low‑rank adapters (LoRA) in large language models. By rewriting each adapter into a balanced canonical form and enforcing a one‑directional coupling, READ allows new skills to read but never write into the output subspaces of existing skills, eliminating interference. Experiments on four benchmark suites and two model families show that READ consistently outperforms existing baselines, improving SuperGLUE scores by over twenty points and domain suite scores by more than seven points.

By Zeyan Li, Panqi Yang, Qirong Guo, Shengda Zhuo, SIyuan Qiu, Hu Xu, Chun Li, Jianfeng Xu
arXiv AI
Sep 10

FedSubMuon: Communication-Efficient Federated LLM Fine-Tuning via Structured Subspace Muon

FedSubMuon introduces a communication‑efficient federated fine‑tuning approach for large language models by optimizing compact coefficient matrices within shared structured subspaces, thereby keeping Muon’s matrix‑aware optimization while reducing client upload size. An accuracy‑oriented variant, FedSubMuon‑GT, further adapts subspace bases using projected gradients to better align with task‑relevant directions. Experiments on instruction tuning and mathematical reasoning demonstrate that FedSubMuon‑GT achieves the best overall accuracy on most dataset‑model pairs, while FedSubMuon outperforms all matched‑budget baselines and reduces communication by up to 5.5× on Llama‑1B and 1.4× on Qwen‑4B compared to the closest baseline.

By Shaolong Chen, Youming Tao, Shuzhen Chen, Falko Dressler, Qingqing Ye, Di Wang
arXiv AI
Jun 9

Sparrow: Sparse Rollout for Stable and Efficient Long-context RL of Large Language Models

arXiv:2606. 08446v1 Announce Type: cross Abstract: Despite being powerful, reinforcement learning with verifiable rewards (RLVR) induces extremely long COT, making it computationally expensive.

By Yang Zhou, Ranajoy Sadhukhan, Zhaofeng Sun, Zhuoming Chen, Souvik Kundu, Saket Dingliwal, Sai Muralidhar Jayanthi, Aram Galstyan, Haizhong Zheng, Beidi Chen