arXiv AI

From Admission to Retention: Predicting Durable Offspring in Quality-Diversity Search

The paper investigates how to predict which offspring in a Quality‑Diversity (QD) archive will be retained over time, rather than just entering the archive. By analyzing signals available before reproduction, the authors find that lineage depth is the most reliable indicator of long‑term persistence, though its predictive power varies with population size. Despite this insight, biasing parent selection toward these signals does not improve overall search performance and can even lower the QD‑score.

arXiv AI
Oct 28

Repulsive Population Policy Gradients for Behaviorally Diverse Reinforcement Learning

The paper introduces RePPO, a method that adapts Proximal Policy Optimization to jointly optimize a compact population of diverse, high‑quality policies using a population‑dependent, dynamically shaped reward. RePPO achieves a strong quality‑diversity tradeoff on standard continuous‑control tasks and scales to larger policy and behavior spaces, maintaining quality while significantly increasing diversity in pixel‑based tasks. The authors also demonstrate RePPO’s applicability to fine‑tuning large language models, showing for the first time that quality‑diversity reinforcement learning can scale to this domain.

By Saeed Hedayatian, Harsh Shah, Celine Mneimneh, Stefanos Nikolaidis
arXiv AI
Aug 6

Beyond the Dirac Delta: Mitigating Diversity Collapse in Reinforcement Fine-Tuning for Versatile Image Generation

arXiv:2601. 12401v2 Announce Type: replace-cross Abstract: Reinforcement learning (RL) has emerged as a powerful paradigm for fine-tuning large-scale generative models, such as diffusion and flow models, to align with complex human preferences and user-specified tasks.

By Jinmei Liu, Haoru Li, Zhenhong Sun, Chaofeng Chen, Yatao Bian, Bo Wang, Daoyi Dong, Chunlin Chen, Zhi Wang
arXiv AI
Sep 10

SwiftExplorer: Training-free Diffusion Model Alignment with Swift Diversity Exploration

SwiftExplorer is a training‑free diffusion model alignment plugin that addresses two key issues in objective‑guided sampling: the loss of diversity due to strong directional bias and the inefficiency of constant guidance. It introduces an Inheritance‑Restart exploration mechanism to prevent early convergence and enhance the likelihood of high‑reward trajectories, while a Quality‑Efficiency arbitration mechanism removes incorrect signals and dynamically stops generation when optimal reward gain is achieved. Experiments show that SwiftExplorer improves preference, fidelity, diversity, and richness across multiple evaluation metrics.

By Renye Yan, Jikang Cheng, You Wu, Bojin Huang, Wei Peng, Zongwei Wang, Ling Liang, Yimao Cai
arXiv AI
Sep 11

Efficient Diversity-based Experience Replay for Deep Reinforcement Learning

Efficient Diversity-based Experience Replay (EDER) is introduced to enhance learning efficiency in deep reinforcement learning. It uses a determinantal point process to model sample diversity, prioritizes replay based on this diversity, and incorporates Cholesky decomposition and rejection sampling to handle large state spaces. Experiments on MuJoCo, Atari, and Habitat show that EDER significantly improves learning efficiency and performance in high‑dimensional, realistic environments.

By Kaiyan Zhao, Yiming Wang, Yuyang Chen, Yan Li, Leong Hou U, Xiaoguang Niu
arXiv AI
Sep 17

Evolutionary Ensemble Search: Council-Guided Program Evolution with Persistent Memory

Evolutionary Ensemble Search (EES) is a framework that builds machine‑learning procedures through expert‑guided program evolution. A specialized council interprets task evidence and experimental results to generate structured search directions, which an orchestrator assigns to execution specialists and an evolutionary engine. The engine selects parents, diagnoses errors, and creates descendants via code mutation, pipeline edits, and crossover, with each child evaluated on its own validation evidence. Population archives preserve useful alternatives, and compatible predictions compete in a validation‑gated ensemble stage. Search adapts through parent‑relative operator credit, session memory, and lessons retrieved across runs. The system achieved medal‑threshold artifacts on 19 of 22 tasks (86.36 %) with 11 gold, five silver, and three bronze outcomes across diverse modalities.

By Juan P. Madrigal-Cianci, Eshan Chordia
arXiv Computation and Language
Oct 27

Evolving Language Models without Labels: Majority Drives Selection, Novelty Promotes Variation

arXiv:2509.15194v4 Announce Type: replace-cross Abstract: Large language models (LLMs) can improve through reinforcement learning with verifiable rewards (RLVR), but many settings lack reference answ...

By Yujun Zhou, Zhenwen Liang, Haolin Liu, Wenhao Yu, Kishan Panaganti, Linfeng Song, Dian Yu, Xiangliang Zhang, Haitao Mi, Dong Yu