Sublinear Time Eigenvector Approximation via Column Sampling
arXiv:2608.00840
2026
Architecture
1 ideas extracted · analyzed Aug 31, 2026
What the math gives to ML
The paper gives a constructive route to recover outlying eigenspaces of a large bounded symmetric matrix from only a small uniformly sampled set of columns, with the approximation living in the span of those columns. The transferable asset is not merely low-rank approximation, but an explicit spectral criterion: components with eigenvalue magnitude at least \(\epsilon n\) can be approximated with residual \(O(\epsilon n)\) using only \(\tilde O(\log n/\epsilon^4)\) columns. In neural networks, this suggests replacing dense symmetric token-mixing or kernel operations by a landmark-column spectral module, with the sampling budget selected from the desired residual tolerance and the retained rank selected by the outlier threshold.
Ideas from this paper
Unverified
2026
Construct a symmetric token affinity matrix and approximate only its spectrally outlying token-mixing modes using a small set of sampled landmark columns. The resulting low-rank operator replaces an \(O(n^2)\) dense mixer by two skinny matrix multiplications, while the paper's residual guarantee predicts that large-magnitude global interaction modes are preserved.
Useful6/10
Difficulty5/10
Novelty5/10