activity
20082023
most citedAdaGrad stepsizes: Sharp convergence over nonconvex landscapes

170 citations · 909 across the 66 of their papers we have counts for

collaborators
Showing math.NAShow all

17 papers · 1 filter

math.NA2022

Scalable symmetric Tucker tensor decomposition

Ruhui Jin, Joe Kileel, Tamara G. Kolda +1

We study the best low-rank Tucker decomposition of symmetric tensors. The motivating application is decomposing higher-order multivariate moments. Moment tensors have special struc…

math.NA2017★ 16 cited

Learning Dynamical Systems and Bifurcation via Group Sparsity

Hayden Schaeffer, Giang Tran, Rachel Ward

Learning governing equations from a family of data sets which share the same physical laws but differ in bifurcation parameters is challenging. This is due, in part, to the wide ra…

math.NA2016

Batched Stochastic Gradient Descent with Weighted Sampling

Deanna Needell, Rachel Ward

We analyze a batched variant of Stochastic Gradient Descent (SGD) with weighted sampling distribution for smooth and non-smooth objective functions. We show that by distributing th…

math.NA2016★ 47 cited

A near-stationary subspace for ridge approximation

Paul G. Constantine, Armin Eftekhari, Jeffrey Hokanson +1

Response surfaces are common surrogates for expensive computer simulations in engineering analysis. However, the cost of fitting an accurate response surface increases exponentiall…

math.NA2015★ 22 cited

The sample complexity of weighted sparse approximation

Bubacarr Bah, Rachel Ward

For Gaussian sampling matrices, we provide bounds on the minimal number of measurements required to achieve robust weighted sparse recovery guarantees in terms of how well a gi…

math.NA2015★ 24 cited

The local convexity of solving systems of quadratic equations

Chris D. White, Sujay Sanghavi, Rachel Ward

This paper considers the recovery of a rank positive semidefinite matrix from scalar measurements of the form (i.e…

math.NA2013★ 31 cited

Stochastic Gradient Descent, Weighted Sampling, and the Randomized Kaczmarz algorithm

Deanna Needell, Nathan Srebro, Rachel Ward

We obtain an improved finite-sample guarantee on the linear convergence of stochastic gradient descent for smooth and strongly convex objectives, improving from a quadratic depende…

math.NA2012

A symbol-based algorithm for decoding bar codes

Mark Iwen, Fadil Santosa, Rachel Ward

We investigate the problem of decoding a bar code from a signal measured with a hand-held laser-based scanner. Rather than formulating the inverse problem as one of binary image re…

math.NA2012★ 102 cited

Near-optimal compressed sensing guarantees for total variation minimization

Deanna Needell, Rachel Ward

Consider the problem of reconstructing a multidimensional signal from an underdetermined set of measurements, as in the setting of compressed sensing. Without any additional assump…

math.NA2012

Two-subspace Projection Method for Coherent Overdetermined Systems (Technical Report)

Deanna Needell, Rachel Ward

In this technical report we present a Projection onto Convex Sets (POCS) type algorithm for solving systems of linear equations. POCS methods have found many applications ranging f…

math.NA2012

Two-subspace Projection Method for Coherent Overdetermined Systems

Deanna Needell, Rachel Ward

We present a Projection onto Convex Sets (POCS) type algorithm for solving systems of linear equations. POCS methods have found many applications ranging from computer tomography t…

math.NA2011★ 36 cited

Weighted eigenfunction estimates with applications to compressed sensing

Nicolas Burq, Semyon Dyatlov, Rachel Ward +1

Using tools from semiclassical analysis, we give weighted L^\infty estimates for eigenfunctions of strictly convex surfaces of revolution. These estimates give rise to new sampling…

math.NA2011★ 100 cited

Sparse recovery for spherical harmonic expansions

Holger Rauhut, Rachel Ward

We show that sparse spherical harmonic expansions can be efficiently recovered from a small number of randomly chosen samples on the sphere. To establish the main result, we verify…

math.NA2010

Low-rank matrix recovery via iteratively reweighted least squares minimization

Massimo Fornasier, Holger Rauhut, Rachel Ward

We present and analyze an efficient implementation of an iteratively reweighted least squares algorithm for recovering a matrix from a small number of linear measurements. The algo…

math.NA2010★ 5 cited

Sparse Legendre expansions via minimization

Holger Rauhut, Rachel Ward

We consider the problem of recovering polynomials that are sparse with respect to the basis of Legendre polynomials from a small number of random samples. In particular, we show th…

math.NA2009★ 1 cited

Iterative thresholding meets free discontinuity problems

Massimo Fornasier, Rachel Ward

Free-discontinuity problems describe situations where the solution of interest is defined by a function and a lower dimensional set consisting of the discontinuities of the functio…

math.NA2008

Compressed Sensing with Cross Validation

Rachel Ward

Compressed Sensing decoding algorithms can efficiently recover an N dimensional real-valued vector x to within a factor of its best k-term approximation by taking m = 2klog(N/k) me…