Nonconvex optimization meets low-rank matrix factorization: An overview

Y Chi, YM Lu, Y Chen - IEEE Transactions on Signal …, 2019 - ieeexplore.ieee.org
Substantial progress has been made recently on develo** provably accurate and efficient
algorithms for low-rank matrix factorization via nonconvex optimization. While conventional …

Spectral methods for data science: A statistical perspective

Y Chen, Y Chi, J Fan, C Ma - Foundations and Trends® in …, 2021 - nowpublishers.com
Spectral methods have emerged as a simple yet surprisingly effective approach for
extracting information from massive, noisy and incomplete data. In a nutshell, spectral …

High-dimensional limit theorems for sgd: Effective dynamics and critical scaling

G Ben Arous, R Gheissari… - Advances in Neural …, 2022 - proceedings.neurips.cc
We study the scaling limits of stochastic gradient descent (SGD) with constant step-size in
the high-dimensional regime. We prove limit theorems for the trajectories of summary …

Implicit regularization in nonconvex statistical estimation: Gradient descent converges linearly for phase retrieval and matrix completion

C Ma, K Wang, Y Chi, Y Chen - International Conference on …, 2018 - proceedings.mlr.press
Recent years have seen a flurry of activities in designing provably efficient nonconvex
optimization procedures for solving statistical estimation problems. For various problems like …

Gradient descent with random initialization: Fast global convergence for nonconvex phase retrieval

Y Chen, Y Chi, J Fan, C Ma - Mathematical Programming, 2019 - Springer
This paper considers the problem of solving systems of quadratic equations, namely,
recovering an object of interest x^ ♮ ∈ R^ nx♮∈ R n from m quadratic equations/samples …

Derivative-free methods for policy optimization: Guarantees for linear quadratic systems

D Malik, A Pananjady, K Bhatia, K Khamaru… - Journal of Machine …, 2020 - jmlr.org
We study derivative-free methods for policy optimization over the class of linear policies. We
focus on characterizing the convergence rate of these methods when applied to linear …

Overparameterized nonlinear learning: Gradient descent takes the shortest path?

S Oymak, M Soltanolkotabi - International Conference on …, 2019 - proceedings.mlr.press
Many modern learning tasks involve fitting nonlinear models which are trained in an
overparameterized regime where the parameters of the model exceed the size of the …

The numerics of phase retrieval

A Fannjiang, T Strohmer - Acta Numerica, 2020 - cambridge.org
Phase retrieval, ie the problem of recovering a function from the squared magnitude of its
Fourier transform, arises in many applications, such as X-ray crystallography, diffraction …

Phase diagram of stochastic gradient descent in high-dimensional two-layer neural networks

R Veiga, L Stephan, B Loureiro… - Advances in …, 2022 - proceedings.neurips.cc
Despite the non-convex optimization landscape, over-parametrized shallow networks are
able to achieve global convergence under gradient descent. The picture can be radically …

A nonconvex approach for phase retrieval: Reshaped wirtinger flow and incremental algorithms

H Zhang, Y Liang, Y Chi - Journal of Machine Learning Research, 2017 - jmlr.org
We study the problem of solving a quadratic system of equations, ie, recovering a vector
signal x ε R n from its magnitude measurements yi=|〈 ai, x〉|, i= 1,..., m. We develop a …