Liang Shan — LS monogram Liang Shan

01 / Research

Questions I’m interested in.

I’m a slow learner, but I keep learning and moving forward.

Deep Learning

DL / Optimizer / Muon

Muon for Diffusion: Theory and Denoising Dynamics

We study the convergence and spectral learning dynamics of Simplified Muon in diffusion denoising, combining theoretical analysis of linear models with controlled experiments on nonlinear denoising networks.

Large Language Models

LLM / Interpretability / Chain-of-Thought Reasoning

Targeted Retrieval, Compact Representations: How CoT Reasoning Improves Long-Context Counting

Liang Twist Shan, Tianyu Hu, Hao Yan, Yiqiao Zhong

We study why Chain-of-Thought reasoning improves long-context counting across modern LLMs. Our mechanistic analysis reveals a shift from one-shot broad retrieval to iterative targeted retrieval, accompanied by more compact internal counter representations.

LLM / Evaluation / Pairwise Preference

Beyond Scalar Leaderboards: Adaptive Sampling for Pareto Frontier Identification in Multi-Objective LLM Arenas

Liang Twist Shan, Jiahao Ai, Zhimei Ren

We study fixed-confidence Pareto frontier identification from multi-objective pairwise preferences, develop an adaptive elimination algorithm with instance-dependent minimax guarantee on sample complexity, and evaluate it on synthetic benchmarks and real-world LLM Arena data.

LLM / Application / Router

Statistical Modeling for Prompt-Dependent LLM Routing

We develop statistical models for prompt-dependent LLM routing from pairwise preferences, exploring prompt and model representations and trade-offs among response quality, cost, and latency.

Diffusion Language Models

DLM / Interpretability / Latent Reasoning

Mechanistic Interpretability of Latent Reasoning in DLMs

We study how diffusion language models represent and update latent reasoning states, and how these mechanisms change across architectures and decoding algorithms.

Agents

Agent / Safety / Memory Monitoring

Memory and Safety Control of LLM Agents

We investigate how LLM agents maintain safety-critical information in internal activations and external memory, and whether monitoring these states can detect mistakes, overlooked requirements, or inaccurate success reports in controlled tasks.