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Andi Han

27 accepted papers

2026

ATOM: A Pretrained Neural Operator for Multitask Molecular Dynamics

ICLR 2026poster

Molecular dynamics (MD) simulations underpin modern computational drug discovery, materials science, and biochemistry. Recent machine learning models provide high-fidelity MD predictions without the need for repeated quantum-mechanical force calculations, enabling significant speedups over conventio…

Cited by 0SourcecodeScholar
2026

Expanding the Chaos: Neural Operator for Stochastic (Partial) Differential Equations

ICML 2026poster

Stochastic differential equations (SDEs) and stochastic partial differential equations (SPDEs) are fundamental for modeling stochastic dynamics across the natural sciences and modern machine learning. Learning their solution operators with deep learning models promises fast solvers and new perspecti…

Cited by 0SourceScholar
2026

Learning Manifold and Itô Dynamics with Branched Neural Rough Differential Equations

ICML 2026poster

Neural rough differential equations (NRDEs) learn continuous-time dynamics from irregularly sampled sequences by encoding the input path with signature features, providing robustness to discretisation and sampling irregularity. However, existing NRDEs implicitly rely on algebraic identities that can…

Cited by 0SourceScholar
2026

On the Learning Dynamics of Two-layer Linear Networks with Label Noise SGD

AAAI 2026technical

One crucial factor behind the success of deep learning lies in the implicit bias induced by noise inherent in gradient-based training algorithms. Motivated by empirical observations that training with noisy labels improves model generalization, we delve into the underlying mechanisms behind stochast

Cited by 0SourcePDFScholar
2026

Provable Sample Efficiency of Curriculum Post-Training for Transformer Reasoning

ICML 2026poster

Recent curriculum techniques in the post-training stage of LLMs have been empirically observed to outperform non-curriculum approaches in improving reasoning performance, yet a principled understanding of their effectiveness and limitations remains incomplete. To bridge this gap, we develop an abstr…

Cited by 0SourceScholar
2026

S$^3$GNN: Efficient Global Mixing and Local Message Passing for Long-Range Graph Learning

ICML 2026spotlight

Message-passing neural networks (MPNNs) often suffer from an information bottleneck when capturing long-range dependencies, leading to the oversquashing (OSQ) phenomenon. Alongside spatial connectivity enrichment (e.g., rewiring), recent studies have shown that spectral filtering can yield strong lo…

Cited by 0SourceScholar
2026

Turning Internal Gap into Self-Improvement: Promoting the Generation-Understanding Unification in MLLMs

ICLR 2026poster

Although unified MLLMs aim to unify generation and understanding, they are considered to exhibit an internal gap, with understanding outperforming generation. Through large‑scale evaluation across multiple MLLMs and tasks, we confirm the widespread non‑unification of MLLMs, and demonstrate that it i…

Cited by 0SourceScholar
2025

ACT as Human: Multimodal Large Language Model Data Annotation with Critical Thinking

NeurIPS 2025poster

Supervised learning relies on high-quality labeled data, but obtaining such data through human annotation is both expensive and time-consuming. Recent work explores using large language models (LLMs) for annotation, but LLM-generated labels still fall short of human-level quality. To address this pr…

Cited by 0SourceScholar
2025

Can Diffusion Models Learn Hidden Inter-Feature Rules Behind Images?

ICML 2025poster

Despite the remarkable success of diffusion models (DMs) in data generation, they exhibit specific failure cases with unsatisfactory outputs. We focus on one such limitation: the ability of DMs to learn hidden rules between image features. Specifically, for image data with dependent features ($\math…

Cited by 1SourcePDFScholar
2025

Diffusing to the Top: Boost Graph Neural Networks with Minimal Hyperparameter Tuning

ICLR 2025poster

Graph Neural Networks (GNNs) are proficient in graph representation learning and achieve promising performance on versatile tasks such as node classification and link prediction. Usually, a comprehensive hyperparameter tuning is essential for fully unlocking GNN's top performance, especially for com…

2025

Efficient Optimization with Orthogonality Constraint: a Randomized Riemannian Submanifold Method

ICML 2025poster

Optimization with orthogonality constraints frequently arises in various fields such as machine learning. Riemannian optimization offers a powerful framework for solving these problems by equipping the constraint set with a Riemannian manifold structure and performing optimization intrinsically on t…

2025

Generalization Bound of Gradient Flow through Training Trajectory and Data-dependent Kernel

NeurIPS 2025poster

Gradient-based optimization methods have shown remarkable empirical success, yet their theoretical generalization properties remain only partially understood. In this paper, we establish a generalization bound for gradient flow that aligns with the classical Rademacher complexity bounds for kernel m…

Cited by 0SourceScholar
2025

How Does Label Noise Gradient Descent Improve Generalization in the Low SNR Regime?

NeurIPS 2025poster

The capacity of deep learning models is often large enough to both learn the underlying statistical signal and overfit to noise in the training set. This noise memorization can be harmful especially for data with a low signal-to-noise ratio (SNR), leading to poor generalization. Inspired by prior ob…

Cited by 0SourceScholar
2025

On the Optimization and Generalization of Two-layer Transformers with Sign Gradient Descent

ICLR 2025spotlight

The Adam optimizer is widely used for transformer optimization in practice, which makes understanding the underlying optimization mechanisms an important problem. However, due to the Adam's complexity, theoretical analysis of how it optimizes transformers remains a challenging task. Fortunately, Si…

Cited by 3SourcePDFScholar
2025

On the Role of Label Noise in the Feature Learning Process

ICML 2025poster

Deep learning with noisy labels presents significant challenges. In this work, we theoretically characterize the role of label noise from a feature learning perspective. Specifically, we consider a signal-noise data distribution, where each sample comprises a label-dependent signal and label-indepen…

2025

Provable In-Context Vector Arithmetic via Retrieving Task Concepts

ICML 2025poster

In-context learning (ICL) has garnered significant attention for its ability to grasp functions/tasks from demonstrations. Recent studies suggest the presence of a latent **task/function vector** in LLMs during ICL. Merullo et al. (2024) showed that LLMs leverage this vector alongside the residual s…

Cited by 0SourcePDFScholar
2025

When Graph Neural Networks Meet Dynamic Mode Decomposition

ICLR 2025poster

Graph Neural Networks (GNNs) have emerged as fundamental tools for a wide range of prediction tasks on graph-structured data. Recent studies have drawn analogies between GNN feature propagation and diffusion processes, which can be interpreted as dynamical systems. In this paper, we delve deeper int…

Cited by 0SourcePDFScholar
2024

A Framework for Bilevel Optimization on Riemannian Manifolds

NeurIPS 2024poster

Bilevel optimization has gained prominence in various applications. In this study, we introduce a framework for solving bilevel optimization problems, where the variables in both the lower and upper levels are constrained on Riemannian manifolds. We present several hypergradient estimation strategie…

2024

On the Comparison between Multi-modal and Single-modal Contrastive Learning

NeurIPS 2024poster

Multi-modal contrastive learning with language supervision has presented a paradigm shift in modern machine learning. By pre-training on a web-scale dataset, multi-modal contrastive learning can learn high-quality representations that exhibit impressive robustness and transferability. Despite its em…

Cited by 6SourcePDFScholar
2024

Provably Transformers Harness Multi-Concept Word Semantics for Efficient In-Context Learning

NeurIPS 2024poster

Transformer-based large language models (LLMs) have displayed remarkable creative prowess and emergence capabilities. Existing empirical studies have revealed a strong connection between these LLMs' impressive emergence abilities and their in-context learning (ICL) capacity, allowing them to solve n…

Cited by 0SourcePDFScholar
2024

SLTrain: a sparse plus low rank approach for parameter and memory efficient pretraining

NeurIPS 2024poster

Large language models (LLMs) have shown impressive capabilities across various tasks. However, training LLMs from scratch requires significant computational power and extensive memory capacity. Recent studies have explored low-rank structures on weights for efficient fine-tuning in terms of paramete…

2023

Riemannian Accelerated Gradient Methods via Extrapolation

AISTATS 2023poster

In this paper, we propose a convergence acceleration scheme for general Riemannian optimization problems by extrapolating iterates on manifolds. We show that when the iterates are generated from the Riemannian gradient descent method, the scheme achieves the optimal convergence rate asymptotically a…

Cited by 10SourcePDFScholar
2021

On Riemannian Optimization over Positive Definite Matrices with the Bures-Wasserstein Geometry

NeurIPS 2021poster

In this paper, we comparatively analyze the Bures-Wasserstein (BW) geometry with the popular Affine-Invariant (AI) geometry for Riemannian optimization on the symmetric positive definite (SPD) matrix manifold. Our study begins with an observation that the BW metric has a linear dependence on SPD mat…