Accelerated gradient methods for geodesically convex optimization: Tractable algorithms and convergence analysis

J Kim, I Yang - International Conference on Machine …, 2022 - proceedings.mlr.press
We propose computationally tractable accelerated first-order methods for Riemannian
optimization, extending the Nesterov accelerated gradient (NAG) method. For both …

On quantum speedups for nonconvex optimization via quantum tunneling walks

Y Liu, WJ Su, T Li - Quantum, 2023 - quantum-journal.org
Classical algorithms are often not effective for solving nonconvex optimization problems
where local minima are separated by high barriers. In this paper, we explore possible …

Infeasible deterministic, stochastic, and variance-reduction algorithms for optimization under orthogonality constraints

P Ablin, S Vary, B Gao, PA Absil - arXiv preprint arXiv:2303.16510, 2023 - arxiv.org
Orthogonality constraints naturally appear in many machine learning problems, from
Principal Components Analysis to robust neural network training. They are usually solved …

Curvature and complexity: Better lower bounds for geodesically convex optimization

C Criscitiello, N Boumal - The Thirty Sixth Annual …, 2023 - proceedings.mlr.press
We study the query complexity of geodesically convex (g-convex) optimization on a
manifold. To isolate the effect of that manifold's curvature, we primarily focus on hyperbolic …

Global Riemannian acceleration in hyperbolic and spherical spaces

D Martínez-Rubio - International Conference on Algorithmic …, 2022 - proceedings.mlr.press
We further research on the accelerated optimization phenomenon on Riemannian manifolds
by introducing accelerated global first-order methods for the optimization of $ L $-smooth …

Interior-point methods on manifolds: theory and applications

H Hirai, H Nieuwboer, M Walter - 2023 IEEE 64th Annual …, 2023 - ieeexplore.ieee.org
Interior-point methods offer a highly versatile framework for convex optimization that is
effective in theory and practice. A key notion in their theory is that of a self-concordant …

Accelerated riemannian optimization: Handling constraints with a prox to bound geometric penalties

D Martínez-Rubio, S Pokutta - The Thirty Sixth Annual …, 2023 - proceedings.mlr.press
We propose a globally-accelerated, first-order method for the optimization of smooth and
(strongly or not) geodesically-convex functions in a wide class of Hadamard manifolds. We …

Concentration of empirical barycenters in metric spaces

VE Brunel, J Serres - International Conference on …, 2024 - proceedings.mlr.press
Barycenters (aka Fréchet means) were introduced in statistics in the 1940's and popularized
in the fields of shape statistics and, later, in optimal transport and matrix analysis. They …

Riemannian accelerated gradient methods via extrapolation

A Han, B Mishra, P Jawanpuria… - … Conference on Artificial …, 2023 - proceedings.mlr.press
In this paper, we propose a convergence acceleration scheme for general Riemannian
optimization problems by extrapolating iterates on manifolds. We show that when the …

Sion's minimax theorem in geodesic metric spaces and a Riemannian extragradient algorithm

P Zhang, J Zhang, S Sra - SIAM Journal on Optimization, 2023 - SIAM
Deciding whether saddle points exist or are approximable for nonconvex-nonconcave
problems is usually intractable. This paper takes a step towards understanding a broad …