Nonconvex optimization meets low-rank matrix factorization: An overview
Substantial progress has been made recently on develo** provably accurate and efficient
algorithms for low-rank matrix factorization via nonconvex optimization. While conventional …
algorithms for low-rank matrix factorization via nonconvex optimization. While conventional …
Spectral methods for data science: A statistical perspective
Spectral methods have emerged as a simple yet surprisingly effective approach for
extracting information from massive, noisy and incomplete data. In a nutshell, spectral …
extracting information from massive, noisy and incomplete data. In a nutshell, spectral …
High-dimensional limit theorems for sgd: Effective dynamics and critical scaling
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 …
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
Recent years have seen a flurry of activities in designing provably efficient nonconvex
optimization procedures for solving statistical estimation problems. For various problems like …
optimization procedures for solving statistical estimation problems. For various problems like …
Gradient descent with random initialization: Fast global convergence for nonconvex phase retrieval
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 …
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
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 …
focus on characterizing the convergence rate of these methods when applied to linear …
Overparameterized nonlinear learning: Gradient descent takes the shortest path?
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 …
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 …
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
Despite the non-convex optimization landscape, over-parametrized shallow networks are
able to achieve global convergence under gradient descent. The picture can be radically …
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
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 …
signal x ε R n from its magnitude measurements yi=|〈 ai, x〉|, i= 1,..., m. We develop a …