collaborators

6 papers

cs.LG2026

Flipping Against All Odds: Reducing LLM Coin Flip Bias via Verbalized Rejection Sampling

Tim Z. Xiao, Johannes Zenn, Zhen Liu +3

Large language models (LLMs) can often accurately describe probability distributions using natural language, yet they still struggle to generate faithful samples from them. This mi…

cs.LG2026

Value Gradient Guidance for Flow Matching Alignment

Zhen Liu, Tim Z. Xiao, Carles Domingo-Enrich +2

While methods exist for aligning flow matching models--a popular and effective class of generative models--with human preferences, existing approaches fail to achieve both adaptati…

cs.LG2025

Efficient Diversity-Preserving Diffusion Alignment via Gradient-Informed GFlowNets

Zhen Liu, Tim Z. Xiao, Weiyang Liu +2

While one commonly trains large diffusion models by collecting datasets on target downstream tasks, it is often desired to align and finetune pretrained diffusion models with some…

cs.AI2025

Generating Symbolic World Models via Test-time Scaling of Large Language Models

Zhouliang Yu, Yuhuan Yuan, Tim Z. Xiao +5

Solving complex planning problems requires Large Language Models (LLMs) to explicitly model the state transition to avoid rule violations, comply with constraints, and ensure optim…

cs.CL2025

Your Finetuned Large Language Model is Already a Powerful Out-of-distribution Detector

Andi Zhang, Tim Z. Xiao, Weiyang Liu +2

We revisit the likelihood ratio between a pretrained large language model (LLM) and its finetuned variant as a criterion for out-of-distribution (OOD) detection. The intuition behi…

cs.LG2025

Verbalized Machine Learning: Revisiting Machine Learning with Language Models

Tim Z. Xiao, Robert Bamler, Bernhard Schölkopf +1

Motivated by the progress made by large language models (LLMs), we introduce the framework of verbalized machine learning (VML). In contrast to conventional machine learning (ML) m…