arXiv Machine Learning

Multi-Agent Coordination via Support-Preserving Distillation

The paper introduces Mode‑Support Semi‑Discrete Optimal Transport (MoSDOT) to address a failure mode in offline multi‑agent reinforcement learning where flow‑based teachers produce conflicting coordination modes. MoSDOT aggregates multimodal replay into a finite mode support with specified capacities and assigns each noise sample to a single mode before teacher training, thereby preventing the teacher from generating samples between valid modes. Experiments on controlled diagnostics and offline MARL benchmarks show that MoSDOT improves endpoint quality and routing consistency, especially on datasets with multimodal joint behavior.

arXiv Machine Learning
Oct 5

Test-time Multi-agent Coordination by Decomposed Value Gradient Flow

The paper introduces SCOUT, an offline multi-agent reinforcement learning framework that combines a generative behavioral prior with a decomposed value function for test-time action refinement. SCOUT uses optimal unified transport and Stein variational gradient descent to steer behavioral samples toward high-value regions, with the number of transport steps providing adaptive scaling. The authors prove a single-term KL bound on the joint soft-value gap under the individual-global-max principle and demonstrate that SCOUT outperforms existing methods on both discrete and continuous offline MARL benchmarks, including offline-to-online settings.

By Dongsu Lee, Haoran Xu, Amy Zhang
arXiv Machine Learning
Oct 8

Composing What Each Teacher Learned: Multi-Teacher On-Policy Distillation through Teacher-Relative Shifts

The paper introduces Δ‑MOPD, a multi‑teacher on‑policy distillation method that transfers each teacher’s logit shift relative to its base policy, re‑anchored at the student’s frozen initialization. Δ‑MOPD is evaluated in two settings: common‑domain composition, where multiple teachers score a single student rollout, and routed‑domain distillation, where prompts are assigned to specialist teachers. Across experiments, Δ‑MOPD outperforms traditional endpoint supervision, especially when teacher signals are combined at a state, achieving higher accuracy and reducing performance gaps in phased routing scenarios.

By Hejian Sang, Zhengze Zhou, Shayan Mohajer Hamidi, Xiaomin Li, Rohit Jain, Alborz Geramifard
arXiv Computer Vision
Oct 5

VDOT++: Unified Few-Step Video Generation via Unbalanced Optimal Transport Distillation

The paper introduces VDOT++, a unified distillation framework for few-step video generation across text-to-video, image-to-video, and condition-based tasks. It extends the previous VDOT method by incorporating an asymmetric unbalanced optimal transport distillation that allows student tokens to carry less mass, and an α1 ground cost that uses a weighted median to preserve modes. The approach combines distribution matching with adversarial refinement and cross-scale distillation, achieving competitive performance on multiple video benchmarks with only four sampling steps.

By Yutong Wang, Xingtong Ge, Enhuai Liu, Yunke Wang, Tianfan Xue, Yu Qiao, Yaohui Wang, Xinyuan Chen, Chang Xu
arXiv AI
Oct 12

Beyond Domain-Routed Supervision: Cross-Teacher Guarding for Multi-Teacher On-Policy Distillation

The paper introduces Cross-Teacher Guarding for Multi-Teacher On-Policy Distillation (Road MOPD), a method that adds non-routed teachers as auxiliary cross-domain critics to address gradient conflicts in multi-teacher distillation. It employs token-level credit assignment based on teacher agreement and preventive gradient projection to coordinate updates and reduce conflicts. Experiments show that Road MOPD improves performance, especially in high-conflict scenarios, and mitigates degradation in disadvantaged domains.

By Shi-Yu Tian, Yong Liu, Ximan Liu, Tianrui Zhu, Sule Bai, Xinwei Yang, Ruiqi Liu, Kun-Yang Yu, Ming Yang, Zhi Zhou, Yu-Feng Li, Yipeng Sun, Gu Simiu
arXiv Machine Learning
Sep 10

Distillation as Probability Transport: Routed On-Policy Distillation

The paper introduces RouteOPD, a new on‑policy distillation method that treats teacher‑student disagreement as a probability transport problem. By decomposing disagreement into excess sources and deficit destinations, RouteOPD pairs them explicitly and optimizes pairwise log‑odds toward targets derived from a bounded teacher potential. Experiments on four teacher‑student configurations and four mathematical‑reasoning benchmarks show that RouteOPD consistently outperforms sampled reverse‑KL OPD, achieving higher routing fidelity and lower background leakage.

By Tianle Xia, Lingxiang Hu, Yiding Sun, Linfang Shang, Ming Xu, Lan Xu, Ning Zheng, Wei Xu, Jie Jiang
arXiv AI
Sep 15

Counteraction-Aware Multi-Teacher On-Policy Distillation for General Capability Recovery with Domain Preservation

The paper introduces Counteraction-Aware Multi-Teacher On-Policy Distillation (CaMOPD), a method designed to recover general capabilities in large language models while preserving domain-specific behavior. CaMOPD tackles two failure modes of standard Multi-Teacher On-Policy Distillation—conflicting recovery and preservation gradients, and weak correction signals—by using decoupled alternating training and selecting samples with large teacher‑student log‑probability gaps. Experiments on role‑play dialogue and medical reasoning QA show that CaMOPD outperforms baselines in general capability recovery while maintaining domain specialization, and gradient coherence analyses confirm more coherent correction signals.

By Tianlei Chen, Jiao Ou, Ziyuan Liu, Ruiming Tang, Jian Liang, Han Li