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Zhengchao Wan

10 accepted papers

2026

Two Calm Ends and the Wild Middle: A Geometric Picture of Memorization in Diffusion Models

ICML 2026poster

Diffusion models generate high-quality samples but can also memorize training data, raising serious privacy concerns. Understanding the mechanisms governing when memorization versus generalization occurs remains an active area of research. In particular, it is unclear where along the noise schedule …

Cited by 0SourceScholar
2025

Elucidating Flow Matching ODE Dynamics via Data Geometry and Denoisers

ICML 2025poster

Flow matching (FM) models extend ODE sampler based diffusion models into a general framework, significantly reducing sampling steps through learned vector fields. However, the theoretical understanding of FM models, particularly how their sample trajectories interact with underlying data geometry, r…

Cited by 0SourcePDFScholar
2025

Seeds of Structure: Patch PCA Reveals Universal Compositional Cues in Diffusion Models

NeurIPS 2025poster

Diffusion models transform random noise into images of remarkable fidelity, yet the structure of this noise-to-image map remains largely unexplored. We investigate this relationship using patch-wise Principal Component Analysis (PCA) and empirically demonstrate that low-frequency components of the i…

Cited by 0SourceScholar
2024

Comparing Graph Transformers via Positional Encodings

ICML 2024poster

The distinguishing power of graph transformers is tied to the choice of *positional encoding*: features used to augment the base transformer with information about the graph. There are two primary types of positional encoding: *absolute positional encodings (APEs)* and *relative positional encodings…

2024

Continuous Partitioning for Graph-Based Semi-Supervised Learning

NeurIPS 2024poster

Laplace learning algorithms for graph-based semi-supervised learning have been shown to produce degenerate predictions at low label rates and in imbalanced class regimes, particularly near class boundaries. We propose CutSSL: a framework for graph-based semi-supervised learning based on continuous n…

Cited by 1SourcePDFScholar
2023

The Numerical Stability of Hyperbolic Representation Learning

ICML 2023poster

The hyperbolic space is widely used for representing hierarchical datasets due to its ability to embed trees with small distortion. However, this property comes at a price of numerical instability such that training hyperbolic learning models will sometimes lead to catastrophic NaN problems, encount…

2023

The Persistent Laplacian for Data Science: Evaluating Higher-Order Persistent Spectral Representations of Data

ICML 2023poster

Persistent homology is arguably the most successful technique in Topological Data Analysis. It combines homology, a topological feature of a data set, with persistence, which tracks the evolution of homology over different scales. The persistent Laplacian is a recent theoretical development that com…

Cited by 6SourcePDFScholar
2023

Understanding Oversquashing in GNNs through the Lens of Effective Resistance

ICML 2023poster

Message passing graph neural networks (GNNs) are a popular learning architectures for graph-structured data. However, one problem GNNs experience is oversquashing, where a GNN has difficulty sending information between distant nodes. Understanding and mitigating oversquashing has recently received s…

2022

Weisfeiler-Lehman Meets Gromov-Wasserstein

ICML 2022spotlight

The Weisfeiler-Lehman (WL) test is a classical procedure for graph isomorphism testing. The WL test has also been widely used both for designing graph kernels and for analyzing graph neural networks. In this paper, we propose the Weisfeiler-Lehman (WL) distance, a notion of distance between labeled…