arXiv Machine Learning

Curvature-Guided LoRA: Matching Full Fine-Tuning in Function Space

arXiv:2603. 29824v2 Announce Type: replace Abstract: Parameter-efficient fine-tuning methods such as LoRA enable efficient adaptation of large pretrained models, but often lag behind full fine-tuning in both convergence speed and final performance.

arXiv Machine Learning
Sep 23

MONA: Muon Optimizer with Nesterov Acceleration for Scalable Language Model Training

MONA is a new optimizer that extends the Muon optimizer by adding a Nesterov‑style acceleration term derived from an exponential moving average of gradient differences. The paper provides a convergence analysis showing that this term offers curvature‑aware corrections while maintaining Muon’s spectral‑norm regularization. Empirical results demonstrate that MONA outperforms both Muon and AdamW on Mixture‑of‑Experts pretraining across models ranging from 1 B to 68 B parameters, and achieves state‑of‑the‑art performance on downstream benchmarks after fine‑tuning the largest model.

By Jiacheng Li, Jianchao Tan, Hongtao Xu, Jiaqi Zhang, Yifan Lu, Yerui Sun, Yuchen Xie, Xunliang Cai
arXiv AI
2d ago

GPart: End-to-End Isometric Fine-Tuning via Global Parameter Partitioning

GPart introduces a new parameter‑efficient fine‑tuning technique that directly maps a low‑dimensional trainable vector into the full weight space using a sparse, isometric partition matrix. Unlike LoRA, GPart eliminates the bilinear reconstruction step, preserving exact end‑to‑end isometry and reducing the checkpoint to just the vector and a random seed. Experiments across NLP, vision, and reasoning tasks show that GPart matches or surpasses existing PEFT methods while using far fewer parameters and offering a simpler, more tractable parameterization.

By Paolo Mandica, Micha{\l} Brzozowski, Zuzanna Dubanowska, Neo Christopher Chung
arXiv Machine Learning
Sep 14

Rank-Efficient LoRA via Joint Tangent-Space Optimization under Isotropic Curvature

The paper introduces ISO-LoRA, an optimizer that improves rank utilization in Low‑Rank Adaptation (LoRA) by coupling factor updates through spectral descent on the induced tangent perturbation in weight space. Experiments on GPT‑2 adaptation show that standard optimizers like AdamW concentrate updates in a few singular directions, whereas ISO-LoRA distributes energy more evenly, leading to higher effective rank and better downstream performance across 0.1B‑7B models. The authors provide theoretical guarantees under a stylized spiked‑gradient model and demonstrate that ISO-LoRA consistently outperforms factor‑wise optimizers, especially at moderate‑to‑large LoRA ranks.

By Zihan Zhu, Zhehang Du, Xuyang Chen, Tim Tsz-Kit Lau, Jiayuan Wu, X. Y. Han, Qi Long, Weijie Su