φ-Balancing for Mixture-of-Experts Training
On the map: Mixture-of-experts → Expert routing strategies
Abstract (arXiv)
Mixture-of-Experts (MoE) models rely on balanced expert utilization to fully realize their scalability. However, existing load-balancing methods are largely heuristic and operate on noisy mini-batch assignment statistics, introducing bias relative to population-level objectives. We propose φ-balancing, a principled framework that directly targets population-level expert balance by minimizing a strictly convex, symmetric, and differentiable potential of the expected routing distribution. Using convex duality, we derive an equivalent min-max formulation and obtain a simple online algorithm via mirror descent, yielding an efficient EMA-based routing adjustment with negligible overhead. Across large-scale pretraining and downstream fine-tuning, φ-balancing consistently outperforms prior Switch-style and loss-free baselines, demonstrating more stable and effective expert utilization.
Key facts. Cited by 5 papers in the map (data through 14 Oct 2026). Placed in Expert routing strategies, one of 12 directions in Mixture-of-experts. Builds on 56 of its 69 references that are in the map. First posted on arXiv 14 May 2026.
Builds on
56 of 69 references.
Closest ancestors · 12
Same direction, newest first
- 2025Coupling Experts and Routers in Mixture-of-Experts via an Auxiliary Loss29 Dec
- 2025ERMoE: Eigen-Reparameterized Mixture-of-Experts for Stable Routing and Interpretable Specialization14 Nov
- 2025Latent Prototype Routing: Achieving Near-Perfect Load Balancing in Mixture-of-Experts26 Jun
- 2025Load Balancing Mixture of Experts with Similarity Preserving Routers16 Jun
- 2024ReMoE: Fully Differentiable Mixture-of-Experts with ReLU Routing19 Dec
- 2024Auxiliary-Loss-Free Load Balancing Strategy for Mixture-of-Experts28 Aug
- 2024Layerwise Recurrent Router for Mixture-of-Experts13 Aug
- 2024AdaMoE: Token-Adaptive Routing with Null Experts for Mixture-of-Experts Language Models19 Jun
- 2022StableMoE: Stable Routing Strategy for Mixture of Experts18 Apr
- 2022Mixture-of-Experts with Expert Choice Routing18 Feb
- 2021Switch Transformers: Scaling to Trillion Parameter Models with Simple and Efficient Sparsity11 Jan
- 2019Hierarchical Routing Mixture of Experts18 Mar
Other references · 44
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Built on by
Citing papers per year: 2026: 5.
5 papers.
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- 2026CIPHER-MoE: Balancing Efficiency and Routing Fidelity in Trillion-Scale MoE Trainingcited by 0
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- 2026How to Loop MoE: Flatten the Experts, Untie the Attention28 Sep 2026
- 2026EntropyMoE: Entropy-Aware Sparse Expert Routing for Tokenizer-Free LLMs31 Jul 2026
- 2026Confidence-Adaptive SwiGLU for Mixture-of-Experts30 May 2026
- 2026Training-Free Looped Transformers22 May 2026
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