arXiv Machine Learning

Best of Both Worlds in Federated LSA: Speedup When Possible, Personalization Always

The paper introduces PF‑LSA, a minimalist algorithm for personalized federated linear stochastic approximation that blends each agent’s local update with a global average. It achieves both fast convergence to each agent’s personalized solution and a linear speedup in the number of agents when their learning problems are similar, without requiring prior knowledge of heterogeneity. The analysis decomposes error into consensus and disagreement components, showing rapid decay of consensus error and negligible disagreement in low‑heterogeneity regimes.

arXiv AI
Sep 2

Provably Efficient Federated Reinforcement Learning with Linear Function Approximation and Logarithmic Communication Cost

The paper introduces Fed‑LSVI, a federated online reinforcement learning algorithm that uses linear function approximation in episodic Markov decision processes. It achieves a regret bound of ≥O(√{Md^3H^4T}) while only exchanging compressed sufficient statistics, thereby meeting privacy constraints. The method reduces communication cost to logarithmic in the number of episodes, a marked improvement over previous approaches that required linear communication.

By Zihang Liang, Haochen Zhang, Lingzhou Xue
arXiv Machine Learning
Aug 27

Differentiated Aggregation to Improve Generalization in Federated Learning

The paper proposes a new federated learning approach called FedALS that reduces communication costs by varying aggregation frequencies across model layers. It derives tighter generalization bounds for one‑round and multi‑round federated learning, linking these bounds to local updates and data heterogeneity. Based on representation‑learning insights, the authors argue that infrequent aggregation of early layers and more frequent aggregation of final layers yields more generalizable models, especially in non‑iid settings, and demonstrate the method’s effectiveness experimentally.

By Peyman Gholami, Hulya Seferoglu
arXiv Machine Learning
Sep 7

Resilience Beyond Stationary Client Unavailability: Unlocking Efficient and Unbiased Federated Learning

The paper introduces FedSWE, a federated learning algorithm designed to handle non‑stationary and heterogeneous client availability without requiring prior real‑time knowledge of which devices are online. FedSWE compensates for missed computations, stabilizes global updates, and mixes local updates through implicit gossiping, all while adding only modest memory and computational overhead. The authors prove that FedSWE converges to a stationary point for non‑convex objectives and achieves linear speedup in certain scenarios, and they validate these claims with experiments on real‑world datasets featuring diverse client unavailability patterns.

By Ming Xiang, Stratis Ioannidis, Edmund Yeh, Carlee Joe-Wong, Lili Su
arXiv Machine Learning
Sep 18

Robust Federated Q-Learning with Almost No Communication

The paper introduces Robust Fed-Q, a federated Q‑learning algorithm designed for settings where multiple agents interact with a shared Markov Decision Process and communicate through a central server. It combines model‑based and model‑free reinforcement learning techniques with a median‑of‑means strategy from robust statistics to handle a small fraction of adversarial agents. The authors prove that Robust Fed-Q achieves exact convergence to the optimal value function with high probability, attains near‑optimal finite‑time rates that benefit from collaboration, and requires only “~O(1)” communication rounds per guarantee.

By Sreejeet Maity, Aritra Mitra
arXiv Machine Learning
Oct 3

Latent Information Sharing for Accelerating Federated Learning

The paper introduces a latent information sharing scheme for federated learning that mitigates client drift by sharing a small amount of hidden‑layer activations. The authors demonstrate both theoretically and empirically that this approach improves training efficiency while maintaining convergence guarantees and data privacy. Compared to existing methods such as FedProx, SCAFFOLD, FedPVR, FedProto, and SplitFed, the proposed method achieves higher model accuracy within a fixed round budget without adding significant communication overhead.

By Seungjun Lee, Ensieh Khazaei, Dimitrios Hatzinakos, Baturalp Buyukates, Sunwoo Lee
arXiv Machine Learning
Sep 22

Personalized Federated Reinforcement Learning via Model-Agnostic Meta-Learning: Convergence of Exact and Hessian-Free Meta-Policy Gradients

arXiv:2609. 22833v1 Announce Type: new Abstract: We study personalized federated reinforcement learning, in which $n$ agents, each acting in its own Markov decision process, collaborate through a server to learn a shared MAML-style policy initialization that becomes effective for an individual agent once that agent adapts it with a single local policy-gradient step.

By Ali Beikmohammadi, Sarit Khirirat, Sindri Magn\'usson
arXiv Machine Learning
Jun 10

FedSLoP: Memory-Efficient Federated Learning with Low-Rank Gradient Projection

arXiv:2604. 24012v3 Announce Type: replace Abstract: Federated learning enables a population of clients to collaboratively train machine learning models without exchanging their raw data, but standard algorithms such as FedAvg suffer from slow convergence and high communication and memory costs in heterogeneous, resource-constrained environments.

By Yutong He, Zhengyang Huang, Jiahe Geng, Kun Yuan