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Foivos Alimisis

5 accepted papers

2021

Communication-Efficient Distributed Optimization with Quantized Preconditioners

ICML 2021spotlight

We investigate fast and communication-efficient algorithms for the classic problem of minimizing a sum of strongly convex and smooth functions that are distributed among $n$ different nodes, which can communicate using a limited number of bits. Most previous communication-efficient approaches for th…

Cited by 25SourcePDFScholar
2021

Distributed Principal Component Analysis with Limited Communication

NeurIPS 2021poster

We study efficient distributed algorithms for the fundamental problem of principal component analysis and leading eigenvector computation on the sphere, when the data are randomly distributed among a set of computational nodes. We propose a new quantized variant of Riemannian gradient descent to so…

2021

Momentum Improves Optimization on Riemannian Manifolds

AISTATS 2021poster

We develop a new Riemannian descent algorithm that relies on momentum to improve over existing first-order methods for geodesically convex optimization. In contrast, accelerated convergence rates proved in prior work have only been shown to hold for geodesically strongly-convex objective functions.…

2020

A Continuous-time Perspective for Modeling Acceleration in Riemannian Optimization

AISTATS 2020poster

We propose a novel second-order ODE as the continuous-time limit of a Riemannian accelerated gradient-based method on a manifold with curvature bounded from below. This ODE can be seen as a generalization of the ODE derived for Euclidean spaces, and can also serve as an analysis tool. We analyze th…