arXiv AI

Linear Algebra Foundations of Efficient Attention: A Phase Reversal in Rank Collapse Under SVD Compression

arXiv Computation and Language
Oct 1

Learning Functional Subspaces for Neural Network Compression

arXiv:2609.40127v1 Announce Type: cross Abstract: Modern transformers pair impressive capabilities with substantial memory and compute demands. Low-rank weight factorization reduces both while keepin...

By Massimo Bini, Anders Christensen, Stephan Alaniz, Judah Goldfeder, Ole Winther, Yann LeCun, Ravid Shwartz-Ziv, Zeynep Akata
arXiv AI
6d ago

SVD-Attention: Efficiently Analyzing Attention Blocks in Transformers

SVD-Attention is a post‑hoc diagnostic tool that decomposes each self‑attention head’s interaction matrix into singular modes, scoring them by spectral magnitude and token‑wise activation variance on a small calibration set. The method retains only the modes that the head can amplify and that are actually activated by real data, producing an exact factorization without finetuning. Across seven pretrained models and five tasks, the analysis reveals task‑dependent redundancy patterns and shows that truncating the identified redundant layers incurs minimal performance loss while truncating other layers can cause significant degradation.

By Debopam Sanyal, Hongjie Chen, Riya Elizabeth Kuriyan, Arth Tak, Divya Kothandaraman, Akshay Mehra, Joshua Kimball, Alexey Tumanov
arXiv Computer Vision
Oct 22

Training-free Acceleration for Blind Compressed Image Restoration via Activation-Calibrated Singular Value Decomposition

The paper proposes a training‑free acceleration technique for transformer‑based blind compressed image restoration models. By profiling computation hotspots and channel‑wise activation distributions, the authors identify recurrent projection operators that can be replaced with low‑rank approximations. They introduce Activation‑Calibrated Singular Value Decomposition (ASVD), which derives low‑rank factors offline from pretrained weights and a few calibration images, achieving significant parameter and computation reductions while improving PSNR‑B over a TSVD baseline.

By Suhang Yao, Xin Li, Xijun Wang, Yufei Wang, Yeying Jin, Zhibo Chen
arXiv AI
6d ago

Subspace Crystallization in Grokking: Rank Compression Tracks the Phase Transition

The paper investigates the relationship between rank compression of weight matrices and the phenomenon of grokking in neural networks. Using a mean‑field MLP and a one‑layer transformer trained on modular arithmetic, the authors find that rank compression occurs after the onset of grokking, not during memorization, and that the effective rank drops sharply around 900 steps following the grokking onset. They also observe a subspace crystallization effect, where the number of singular directions needed to preserve test accuracy shrinks dramatically during the transition, and demonstrate that artificially imposing low rank does not accelerate grokking, indicating that compression is a signature rather than a cause of the phenomenon.

By Shlok Mehendale, Paras Chopra