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Geovani Rizk

5 accepted papers

2025

Adaptive Gradient Clipping for Robust Federated Learning

ICLR 2025spotlight

Robust federated learning aims to maintain reliable performance despite the presence of adversarial or misbehaving workers. While state-of-the-art (SOTA) robust distributed gradient descent (Robust-DGD) methods were proven theoretically optimal, their empirical success has often relied on pre-aggreg…

Cited by 0SourcePDFScholar
2024

Byzantine-Robust Federated Learning: Impact of Client Subsampling and Local Updates

ICML 2024poster

The possibility of adversarial (a.k.a., Byzantine) clients makes federated learning (FL) prone to arbitrary manipulation. The natural approach to robustify FL against adversarial clients is to replace the simple averaging operation at the server in the standard $\mathsf{FedAvg}$ algorithm by a robus…

Cited by 5SourcePDFScholar
2023

Robust Distributed Learning: Tight Error Bounds and Breakdown Point under Data Heterogeneity

NeurIPS 2023spotlight

The theory underlying robust distributed learning algorithms, designed to resist adversarial machines, matches empirical observations when data is homogeneous. Under data heterogeneity however, which is the norm in practical scenarios, established lower bounds on the learning error are essentially v…

Cited by 20SourcePDFScholar
2022

An $\alpha$-No-Regret Algorithm For Graphical Bilinear Bandits

NeurIPS 2022accept

We propose the first regret-based approach to the \emph{Graphical Bilinear Bandits} problem, where $n$ agents in a graph play a stochastic bilinear bandit game with each of their neighbors. This setting reveals a combinatorial NP-hard problem that prevents the use of any existing regret-based algori…

Cited by 0SourcePDFScholar
2021

Best Arm Identification in Graphical Bilinear Bandits

ICML 2021spotlight

We introduce a new graphical bilinear bandit problem where a learner (or a \emph{central entity}) allocates arms to the nodes of a graph and observes for each edge a noisy bilinear reward representing the interaction between the two end nodes. We study the best arm identification problem in which th…

Cited by 7SourcePDFScholar