arXiv Machine Learning

Improving the Optimization Landscape of Matrix Completion with $\epsilon$-close Surrogates

The paper proposes a new approach to matrix completion by adding small (ε-level) perturbations to the nullspace of the observation mask, creating noisy surrogates that remain close to the true matrix. These surrogates satisfy a restricted isometry property, enabling the use of tensor methods with theoretical guarantees. The authors provide quantitative recovery guarantees under independent observation assumptions, without requiring explicit sampling rate or incoherence conditions.

arXiv Machine Learning
Aug 20

Escaping Local Minima Provably in Non-convex Matrix Sensing: A Deterministic Framework via Simulated Lifting

The paper introduces a deterministic Simulated Oracle Direction (SOD) framework that enables escaping spurious local minima in non‑convex low‑rank matrix sensing without explicit tensor lifting. By projecting over‑parameterized escape directions back into the original parameter space, the method guarantees a strict decrease in objective value from existing local minima. Experiments show reliable escape from local minima and convergence to global optima with minimal computational overhead compared to explicit over‑parameterization.

By Tianqi Shen, Jinji Yang, Junze He, Kunhan Gao, Zeyu Zheng, Ziye Ma
arXiv Machine Learning
Sep 16

Near-Optimal Nonconvex Matrix Completion

arXiv:2609. 17048v1 Announce Type: cross Abstract: We study nonconvex methods for matrix completion, the problem of recovering a low-rank matrix from a subset of its entries.

By Jian-Feng Cai, Xiliang Lu, Juntao You
arXiv Machine Learning
Aug 19

Online Generalized Sparse Regression: How Does Overparametrization Help?

The paper introduces an online generalized-sparsity-constrained regression framework that addresses key challenges in online sparse regression, such as dynamic regularization, memory usage, and real-time computation. It proposes an efficient online hard‑thresholding algorithm that performs closed‑form updates using only summary statistics, achieving global convergence at optimal statistical rates when the projection set is overparameterized. Numerical experiments show the method consistently outperforms existing alternatives in online cardinality‑constrained linear regression and low‑rank matrix sensing.

By Shuoguang Yang, Qiang Sun
Hugging Face Trending Papers
Oct 13

Over-parameterization Is Neither Robust nor Fragile in Matrix Sensing: A Geometric Theory of Solution Robustness

The paper investigates how over‑parameterization affects robustness in matrix sensing, a non‑convex problem equivalent to training a two‑layer quadratic neural network. It introduces a rank‑aware robustness theory for the Burer‑Monteiro factorization, showing that robustness depends on both the degree of over‑parameterization and the local geometry of second‑order stationary points. Based on these insights, the authors propose a trajectory‑aware algorithm that steers optimization toward less sensitive solutions, achieving significant reductions in paired sensitivity in experiments without harming reconstruction accuracy.

arXiv Machine Learning
Oct 9

Learning structured linear dynamical systems from missing observations

The paper tackles learning structured linear dynamical systems when only a few observations are available at each time step. It proposes an estimator that minimizes a bias‑corrected, potentially non‑convex objective and derives non‑asymptotic error bounds that depend on the local complexity of the constraint set, the trajectory length, and the sub‑sampling probability. The authors also prove convergence of projected gradient descent and demonstrate the theory for three specific constraint sets, showing that accurate recovery of the transition matrix is achievable with much shorter trajectories and very low observation rates.

By Aravinda Kanchana Ruwanpathirana, Hemant Tyagi, Sunny G. W. Wang
arXiv Machine Learning
Jul 14

Demixing Sparse Signals from Nonlinear Observations using Generalized Non-convex Regularization

arXiv:2607. 10618v1 Announce Type: cross Abstract: We consider the recovery of a pair of sparse vectors from a limited number of nonlinear observations of their superposition: $y_i=g(\inner{\ba_i}{\bPhi\bw^\ast+\bPsi\bz^\ast})+e_i$, $i=1,\dots,m$, with $m\ll n$, incoherent orthonormal bases $\bPhi,\bPsi$, a scalar link $g$, and noise $e_i$ that may be heavy-tailed or contaminated.

By Raziyeh Takbiri