I am a fourth-year Ph.D. candidate in the Department of Computer Science at Rutgers University, advised by Prof. Dimitris N. Metaxas. My research broadly lies at the intersection of large language models, retrieval-augmented generation and information retrieval. I am particularly interested in building reliable retrieval and reasoning frameworks for knowledge-intensive AI systems.

Before joining Rutgers, I received my M.S. degree in Computer Science from Syracuse University in 2022 and my B.Eng. degree from Jilin University in 2020.

I am currently seeking intern/full-time Research Scientist, Applied Scientist, or Machine Learning Engineering opportunities starting in 2026 or early 2027.

Education

 
 
 
 
 
Rutgers, The State University of New Jersey - New Brunswick
Ph.D. Candidate in Computer Science
Sep 2022 – Present Piscataway, NJ, USA
 
 
 
 
 
Syracuse University
M.S. in Computer Science
Sep 2020 – May 2022 Syracuse, NY, USA
 
 
 
 
 
Jilin University
B.Eng. in Logistics Engineering
Sep 2016 – Jul 2020 Changchun, China

Experience

 
 
 
 
 
Computer Science Department, Rutgers University
Research Assistant
Sep 2023 – Present Piscataway, NJ, USA
  • Set-level optimization for relevance-aware diverse retrieval.
  • Agentic GraphRAG for robust reasoning over noisy and incomplete KGs.
  • Pooling & Semantic Shift: A formal theory of long-text embedding retrieval failure.
  • Confidence-guided multimodal Q&A with complementary evidence selection.
 
 
 
 
 
Optical Networking & Sensing, NEC Laboratories America, Inc.
Research Intern
May 2025 – Aug 2025 Princeton, NJ, USA
 
 
 
 
 
College of Engineering And Computer Science, Syracuse University
Research Assistant
Sep 2021 – May 2022 Syracuse, NY, USA

Selected Publications

Pooling and Semantic Shift: the Fundamental Challenge in Long Text Embedding and Retrieval. In arXiv, 2026.
CLIMB: Confidence-Guided Complementary Evidence for Multimodal Retrieval-Augmented Generation. In arXiv, 2026.
A-MEM: Agentic Memory for LLM Agents. In NeurIPS, 2025.
Task-Aligned Tool Recommendation for Large Language Models. In IJCNLP-AACL (Oral), 2025.
Vector Retrieval with Similarity and Diversity: How Hard Is It?. In arXiv, 2024.
2k-Vertex Kernels for Cluster Deletion and Strong Triadic Closure. In Journal of Computer Science and Technology, 2023.

Contact

  • hanggao [dot] gh [at] gmail [dot] com
  • 617 Bowser Rd, Piscataway, NJ 08854