DirMoE: Dirichlet-routed Mixture of Experts

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Vahidi, Amirhossein, Asadollahzadeh, Hesam, Attar, Navid Akhavan, Moullet, Marie, Ly, Kevin, Yang, Xingyi, Lotfollahi, Mohammad
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866910016758349824
author Vahidi, Amirhossein
Asadollahzadeh, Hesam
Attar, Navid Akhavan
Moullet, Marie
Ly, Kevin
Yang, Xingyi
Lotfollahi, Mohammad
author_facet Vahidi, Amirhossein
Asadollahzadeh, Hesam
Attar, Navid Akhavan
Moullet, Marie
Ly, Kevin
Yang, Xingyi
Lotfollahi, Mohammad
contents Mixture-of-Experts (MoE) models have demonstrated exceptional performance in large-scale language models. Existing routers typically rely on non-differentiable Top-$k$+Softmax, limiting their performance and scalability. We argue that two distinct decisions, which experts to activate and how to distribute expert contributions among them, are conflated in standard Top-$k$+Softmax. We introduce Dirichlet-Routed MoE (DirMoE), a novel end-to-end differentiable routing mechanism built on a Dirichlet variational autoencoder framework. This design fundamentally disentangles the core routing problems: expert selection, modeled by a Bernoulli component, and expert contribution among chosen experts, handled by a Dirichlet component. The entire forward pass remains fully differentiable through the use of Gumbel-Sigmoid relaxation for the expert selection and implicit reparameterization for the Dirichlet distribution. Our training objective, a variational ELBO, includes a direct sparsity penalty that precisely controls the number of active experts in expectation, alongside a schedule for key hyperparameters that guides the model from an exploratory to a definitive routing state. Moreover, our DirMoE router matches or exceeds other methods while improving expert specialization.
format Preprint
id arxiv_https___arxiv_org_abs_2602_09001
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle DirMoE: Dirichlet-routed Mixture of Experts
Vahidi, Amirhossein
Asadollahzadeh, Hesam
Attar, Navid Akhavan
Moullet, Marie
Ly, Kevin
Yang, Xingyi
Lotfollahi, Mohammad
Machine Learning
Mixture-of-Experts (MoE) models have demonstrated exceptional performance in large-scale language models. Existing routers typically rely on non-differentiable Top-$k$+Softmax, limiting their performance and scalability. We argue that two distinct decisions, which experts to activate and how to distribute expert contributions among them, are conflated in standard Top-$k$+Softmax. We introduce Dirichlet-Routed MoE (DirMoE), a novel end-to-end differentiable routing mechanism built on a Dirichlet variational autoencoder framework. This design fundamentally disentangles the core routing problems: expert selection, modeled by a Bernoulli component, and expert contribution among chosen experts, handled by a Dirichlet component. The entire forward pass remains fully differentiable through the use of Gumbel-Sigmoid relaxation for the expert selection and implicit reparameterization for the Dirichlet distribution. Our training objective, a variational ELBO, includes a direct sparsity penalty that precisely controls the number of active experts in expectation, alongside a schedule for key hyperparameters that guides the model from an exploratory to a definitive routing state. Moreover, our DirMoE router matches or exceeds other methods while improving expert specialization.
title DirMoE: Dirichlet-routed Mixture of Experts
topic Machine Learning
url https://arxiv.org/abs/2602.09001