arXiv Computer Vision

LoRA Superposition across Pretrained Models

LoRA Superposition across Pretrained Models explores whether low‑rank adaptations (LoRAs) trained independently on different pretrained backbones can be summed and applied unchanged to all contributing backbones. Across seven ViT‑B/16 CLIP backbones and eight image‑classification tasks, the exact sum of LoRAs improves all 56 backbone‑task pairs, achieving a mean accuracy gain of 30.21 percentage points over the unadapted backbone and only 0.28 percentage points below individually trained solo LoRAs. In contrast, a leave‑one‑model‑out sum yields a negligible gain of 0.06 percentage points, and the results suggest that backbone‑specific LoRAs are nearly orthogonal while cross‑backbone responses are concentrated on the diagonal, supporting a component‑wise non‑interference hypothesis.

arXiv Machine Learning
Oct 21

LoRASpace: A Pool-Wide Shared Substrate for Static and Dynamic Multi-LoRA Composition

arXiv:2610.27444v1 Announce Type: cross Abstract: Low-rank adaptation (LoRA) attaches small low-rank matrices to a frozen backbone, and public repositories host many LoRAs per backbone, each for a di...

By Thamirawaran Sathiyalogeswaran, Navindu De Silva, Chamikara Siriwardane, W. K. Alwis, Jason Mars, Udaya Sampath K. Perera Miriya Thanthrige, Ranga Rodrigo
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 Computer Vision
Aug 31

Activation Boundary Matching: Task-Informed Initialization for Low-Rank Adaptation

The paper introduces Activation Boundary Matching for Low‑Rank Adaptation (ABM‑LoRA), a task‑informed initialization strategy that uses the signs of layer‑wise pre‑activations from a brief probe adapter as targets for a fresh adapter. By training with a margin‑based hinge objective on these activation boundaries, ABM‑LoRA captures useful adaptation directions that standard LoRA initializers miss, while requiring only a few forward passes. Experiments show that ABM‑LoRA outperforms or matches existing LoRA, SVD, and gradient‑based initializers across multiple models and benchmarks, including T5‑base/GLUE, ConvNeXt‑T, Swin‑T, Qwen2.5‑1.5B, and LLaMA2‑7B.

By Dongha Lee, Jinhee Park, Minjun Kim, Junseok Kwon
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 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
arXiv Machine Learning
Sep 1

Normalized Low-Rank Adaptation

Normalized Low-Rank Adaptation (NoRA) is a lightweight enhancement to the widely used LoRA technique that normalizes the down‑projection matrices during training. By doing so, NoRA stabilizes early optimization dynamics, accelerates convergence, and improves performance across pretraining, supervised fine‑tuning, and reinforcement learning. The method adds no extra trainable parameters or inference‑time cost, making it broadly applicable.

By Jiale Kang, Ziyin Yue, Zheng Zhan, Yangyi Huang, Weiyang Liu