papers

Publications (24)

cs.LG2022

Adaptive Compression for Communication-Efficient Distributed Training

Maksim Makarenko, Elnur Gasanov, Rustem Islamov +2

We propose Adaptive Compressed Gradient Descent (AdaCGD) - a novel optimization algorithm for communication-efficient training of supervised machine learning models with adaptive c…

cs.LG2026

Double Momentum and Error Feedback for Clipping with Fast Rates and Differential Privacy

Rustem Islamov, Samuel Horvath, Aurelien Lucchi +2

Strong Differential Privacy (DP) and Optimization guarantees are two desirable properties for a method in Federated Learning (FL). However, existing algorithms do not achieve both…

cs.LG2024

Loss Landscape Characterization of Neural Networks without Over-Parametrization

Rustem Islamov, Niccolò Ajroldi, Antonio Orvieto +1

Optimization methods play a crucial role in modern machine learning, powering the remarkable empirical achievements of deep learning models. These successes are even more remarkabl…

cs.LG2025

Adaptive Methods through the Lens of SDEs: Theoretical Insights on the Role of Noise

Enea Monzio Compagnoni, Tianlin Liu, Rustem Islamov +3

Despite the vast empirical evidence supporting the efficacy of adaptive optimization methods in deep learning, their theoretical understanding is far from complete. This work intro…

cs.LG2023

AsGrad: A Sharp Unified Analysis of Asynchronous-SGD Algorithms

Rustem Islamov, Mher Safaryan, Dan Alistarh

We analyze asynchronous-type algorithms for distributed SGD in the heterogeneous setting, where each worker has its own computation and communication speeds, as well as data distri…

cs.LG2021

Basis Matters: Better Communication-Efficient Second Order Methods for Federated Learning

Xun Qian, Rustem Islamov, Mher Safaryan +1

Recent advances in distributed optimization have shown that Newton-type methods with proper communication compression mechanisms can guarantee fast local rates and low communicatio…

math.OC2023

EControl: Fast Distributed Optimization with Compression and Error Control

Yuan Gao, Rustem Islamov, Sebastian Stich

Modern distributed training relies heavily on communication compression to reduce the communication overhead. In this work, we study algorithms employing a popular class of contrac…

cs.LG2026

Byzantine-Robust and Differentially Private Federated Optimization under Weaker Assumptions

Rustem Islamov, Grigory Malinovsky, Alexander Gaponov +3

Federated Learning (FL) enables heterogeneous clients to collaboratively train a shared model without centralizing their raw data, offering an inherent level of privacy. However, g…

cs.LG2026

What's in a Smoothness Constant? Tighter Rates for Local SGD with Bounded Second-order Heterogeneity

Kumar Kshitij Patel, Rustem Islamov, Sebastian U Stich +3

The paper establishes tighter convergence rates for Local SGD (Federated Averaging) on general convex problems under a bounded second‑order heterogeneity assumption, and provides n…

#local sgd#federated learning#convex optimization#heterogeneous data
cs.LG2026

Why Do We Need Warm-up? A Theoretical Perspective

Foivos Alimisis, Rustem Islamov, Aurelien Lucchi

Learning rate warm-up -- increasing the learning rate at the beginning of training -- has become a ubiquitous heuristic in modern deep learning, yet its theoretical foundations rem…

cs.LG2026

Adaptive Methods Are Preferable in High Privacy Settings: An SDE Perspective

Enea Monzio Compagnoni, Alessandro Stanghellini, Rustem Islamov +2

Differential Privacy (DP) is becoming central to large-scale training as privacy regulations tighten. We revisit how DP noise interacts with adaptivity in optimization through the…

cs.LG2021

Distributed Second Order Methods with Fast Rates and Compressed Communication

Rustem Islamov, Xun Qian, Peter Richtárik

We develop several new communication-efficient second-order methods for distributed optimization. Our first method, NEWTON-STAR, is a variant of Newton's method from which it inher…

cs.LG2025

Enhancing Optimizer Stability: Momentum Adaptation of The NGN Step-size

Rustem Islamov, Niccolo Ajroldi, Antonio Orvieto +1

Modern optimization algorithms that incorporate momentum and adaptive step-size offer improved performance in numerous challenging deep learning tasks. However, their effectiveness…

cs.LG2025

Unbiased and Sign Compression in Distributed Learning: Comparing Noise Resilience via SDEs

Enea Monzio Compagnoni, Rustem Islamov, Frank Norbert Proske +1

Distributed methods are essential for handling machine learning pipelines comprising large-scale models and datasets. However, their benefits often come at the cost of increased co…

cs.LG2022

FedNL: Making Newton-Type Methods Applicable to Federated Learning

Mher Safaryan, Rustem Islamov, Xun Qian +1

Inspired by recent work of Islamov et al (2021), we propose a family of Federated Newton Learn (FedNL) methods, which we believe is a marked step in the direction of making second-…

cs.LG2026

Non-Euclidean Gradient Descent Operates at the Edge of Stability

Rustem Islamov, Michael Crawshaw, Jeremy Cohen +1

The Edge of Stability (EoS) is a phenomenon where the sharpness (largest eigenvalue) of the Hessian approaches and then hovers near the stability threshold during gradient d…

cs.LG2026

On the Role of Batch Size in Stochastic Conditional Gradient Methods

Rustem Islamov, Roman Machacek, Aurelien Lucchi +3

We study the role of batch size in stochastic conditional gradient methods under a -Kurdyka-Łojasiewicz (-KL) condition. Focusing on momentum-based stochastic conditional…

cs.LG2022

Distributed Newton-Type Methods with Communication Compression and Bernoulli Aggregation

Rustem Islamov, Xun Qian, Slavomír Hanzely +2

Despite their high computation and communication costs, Newton-type methods remain an appealing option for distributed training due to their robustness against ill-conditioned conv…

cs.LG2024

Towards Faster Decentralized Stochastic Optimization with Communication Compression

Rustem Islamov, Yuan Gao, Sebastian U. Stich

Communication efficiency has garnered significant attention as it is considered the main bottleneck for large-scale decentralized Machine Learning applications in distributed and f…

cs.LG2025

Safe-EF: Error Feedback for Nonsmooth Constrained Optimization

Rustem Islamov, Yarden As, Ilyas Fatkhullin

Federated learning faces severe communication bottlenecks due to the high dimensionality of model updates. Communication compression with contractive compressors (e.g., Top-K) is o…

cs.LG2023

Clip21: Error Feedback for Gradient Clipping

Sarit Khirirat, Eduard Gorbunov, Samuel Horváth +3

Motivated by the increasing popularity and importance of large-scale training under differential privacy (DP) constraints, we study distributed gradient methods with gradient clipp…

cs.LG2026

On the Interaction of Batch Noise, Adaptivity, and Compression, under -Smoothness: An SDE Approach

Enea Monzio Compagnoni, Rustem Islamov, Frank Norbert Proske +3

Distributed stochastic optimization intertwines (i) stochastic gradient noise, (ii) communication compression, and (iii) adaptive/normalized updates. While each factor has been stu…

cs.LG2026

Beyond a Single Explanation of the Adam--SGD Gap

Chenxiang Zhang, Rustem Islamov, Enea Monzio Compagnoni +3

Prior work has identified several factors that can contribute to the performance gap between Adam and SGD, spanning data aspects, architecture design, and optimization properties.…

cs.LG2023

Partially Personalized Federated Learning: Breaking the Curse of Data Heterogeneity

Konstantin Mishchenko, Rustem Islamov, Eduard Gorbunov +1

We present a partially personalized formulation of Federated Learning (FL) that strikes a balance between the flexibility of personalization and cooperativeness of global training.…