activity
20112026
most citedSCAFFOLD: Stochastic Controlled Averaging for Federated Learning

732 citations · 3.2k across the 65 of their papers we have counts for

collaborators

68 papers

cs.LG2026

Optimizers for Diffusion Models: A Controlled Benchmark

Arman Bolatov, Egor Shulgin, David Li +6

Discrete diffusion models now match autoregressive language models on several benchmarks, while the question of how best to train them has received far less attention: the optimize…

cs.LG2026

On the Stability of Nonlinear Dynamics in GD and SGD: Beyond Quadratic Potentials

Rotem Mulayoff, Sebastian U. Stich

The dynamical stability of the iterates during training plays a key role in determining the minima obtained by optimization algorithms. For example, stable solutions of gradient de…

cs.LG2026

Sequential Subspace Noise Injection Prevents Accuracy Collapse in Certified Unlearning

Polina Dolgova, Sebastian U. Stich

Certified unlearning based on differential privacy offers strong guarantees but remains largely impractical: the noisy fine-tuning approaches proposed so far achieve these guarante…

cs.GT2025

Monotone Near-Zero-Sum Games: A Generalization of Convex-Concave Minimax

Ruichen Luo, Sebastian U. Stich, Krishnendu Chatterjee

Zero-sum and non-zero-sum (aka general-sum) games are relevant in a wide range of applications. While general non-zero-sum games are computationally hard, researchers focus on the…

cs.CV2025

Breaking the Likelihood-Quality Trade-off in Diffusion Models by Merging Pretrained Experts

Yasin Esfandiari, Stefan Bauer, Sebastian U. Stich +1

Diffusion models for image generation often exhibit a trade-off between perceptual sample quality and data likelihood: training objectives emphasizing high-noise denoising steps yi…

math.OC2025

Monotone and nonmonotone linearized block coordinate descent methods for nonsmooth composite optimization problems

Yassine Nabou, Lahcen El Bourkhissi, Sebastian U. Stich +1

In this paper, we introduce both monotone and nonmonotone variants of LiBCoD, a \textbf{Li}nearized \textbf{B}lock \textbf{Co}ordinate \textbf{D}escent method for solving composite…

cs.LG2025★ 1 cited

Scalable Decentralized Learning with Teleportation

Yuki Takezawa, Sebastian U. Stich

Decentralized SGD can run with low communication costs, but its sparse communication characteristics deteriorate the convergence rate, especially when the number of nodes is large.…

math.OC2025

Revisiting LocalSGD and SCAFFOLD: Improved Rates and Missing Analysis

Ruichen Luo, Sebastian U Stich, Samuel Horváth +1

LocalSGD and SCAFFOLD are widely used methods in distributed stochastic optimization, with numerous applications in machine learning, large-scale data processing, and federated lea…

cs.LG2024★ 1 cited

The Limits and Potentials of Local SGD for Distributed Heterogeneous Learning with Intermittent Communication

Kumar Kshitij Patel, Margalit Glasgow, Ali Zindari +5

Local SGD is a popular optimization method in distributed learning, often outperforming other algorithms in practice, including mini-batch SGD. Despite this success, theoretically…

math.OC2024

Spectral Preconditioning for Gradient Methods on Graded Non-convex Functions

Nikita Doikov, Sebastian U. Stich, Martin Jaggi

The performance of optimization methods is often tied to the spectrum of the objective Hessian. Yet, conventional assumptions, such as smoothness, do often not enable us to make fi…

cs.LG2023★ 3 cited

Adaptive SGD with Polyak stepsize and Line-search: Robust Convergence and Variance Reduction

Xiaowen Jiang, Sebastian U. Stich

The recently proposed stochastic Polyak stepsize (SPS) and stochastic line-search (SLS) for SGD have shown remarkable effectiveness when training over-parameterized models. However…

cs.LG2023

Locally Adaptive Federated Learning

Sohom Mukherjee, Nicolas Loizou, Sebastian U. Stich

Federated learning is a paradigm of distributed machine learning in which multiple clients coordinate with a central server to learn a model, without sharing their own training dat…

cs.LG2023★ 4 cited

Synthetic data shuffling accelerates the convergence of federated learning under data heterogeneity

Bo Li, Yasin Esfandiari, Mikkel N. Schmidt +2

In federated learning, data heterogeneity is a critical challenge. A straightforward solution is to shuffle the clients' data to homogenize the distribution. However, this may viol…

math.OC2023★ 2 cited

Communication-Efficient Gradient Descent-Accent Methods for Distributed Variational Inequalities: Unified Analysis and Local Updates

Siqi Zhang, Sayantan Choudhury, Sebastian U Stich +1

Distributed and federated learning algorithms and techniques associated primarily with minimization problems. However, with the increase of minimax optimization and variational ine…

cs.LG2023

On Convergence of Incremental Gradient for Non-Convex Smooth Functions

Anastasia Koloskova, Nikita Doikov, Sebastian U. Stich +1

In machine learning and neural network optimization, algorithms like incremental gradient, and shuffle SGD are popular due to minimizing the number of cache misses and good practic…

cs.LG2023★ 4 cited

Revisiting Gradient Clipping: Stochastic bias and tight convergence guarantees

Anastasia Koloskova, Hadrien Hendrikx, Sebastian U. Stich

Gradient clipping is a popular modification to standard (stochastic) gradient descent, at every iteration limiting the gradient norm to a certain value . It is widely used fo…

math.OC2023★ 1 cited

Decentralized Gradient Tracking with Local Steps

Yue Liu, Tao Lin, Anastasia Koloskova +1

Gradient tracking (GT) is an algorithm designed for solving decentralized optimization problems over a network (such as training a machine learning model). A key feature of GT is a…

cs.LG2022★ 4 cited

On the effectiveness of partial variance reduction in federated learning with heterogeneous data

Bo Li, Mikkel N. Schmidt, Tommy S. Alstrøm +1

Data heterogeneity across clients is a key challenge in federated learning. Prior works address this by either aligning client and server models or using control variates to correc…

cs.LG2022★ 18 cited

Sharper Convergence Guarantees for Asynchronous SGD for Distributed and Federated Learning

Anastasia Koloskova, Sebastian U. Stich, Martin Jaggi

We study the asynchronous stochastic gradient descent algorithm for distributed training over workers which have varying computation and communication frequency over time. In t…

cs.LG2022★ 6 cited

Special Properties of Gradient Descent with Large Learning Rates

Amirkeivan Mohtashami, Martin Jaggi, Sebastian Stich

When training neural networks, it has been widely observed that a large step size is essential in stochastic gradient descent (SGD) for obtaining superior models. However, the effe…

cs.LG2022★ 8 cited

Data-heterogeneity-aware Mixing for Decentralized Learning

Yatin Dandi, Anastasia Koloskova, Martin Jaggi +1

Decentralized learning provides an effective framework to train machine learning models with data distributed over arbitrary communication graphs. However, most existing approaches…

cs.LG2022★ 1 cited

Tackling benign nonconvexity with smoothing and stochastic gradients

Harsh Vardhan, Sebastian U. Stich

Non-convex optimization problems are ubiquitous in machine learning, especially in Deep Learning. While such complex problems can often be successfully optimized in practice by usi…

cs.DC2022★ 7 cited

An Improved Analysis of Gradient Tracking for Decentralized Machine Learning

Anastasia Koloskova, Tao Lin, Sebastian U. Stich

We consider decentralized machine learning over a network where the training data is distributed across agents, each of which can compute stochastic model updates on their loca…

cs.LG2022

Characterizing & Finding Good Data Orderings for Fast Convergence of Sequential Gradient Methods

Amirkeivan Mohtashami, Sebastian Stich, Martin Jaggi

While SGD, which samples from the data with replacement is widely studied in theory, a variant called Random Reshuffling (RR) is more common in practice. RR iterates through random…