I am a PhD student at the Athens University of Economics and Business
and an affiliate researcher at Archimedes AI, Athena RC.
My work centers on evaluating and improving how large language models reason over legal text: measuring their legal
reasoning and citation faithfulness, and building practical, grounded LLM applications for law. I am also interested
in what cognitive science reveals about how these models represent meaning.
Publications
2026
The Grounding Gap: How LLMs Anchor the Meaning of Abstract Concepts Differently from Humans
Odysseas S. Chlapanis, Orfeas Menis Mastromichalakis, Christos H. Papadimitriou
Visited Columbia University to work with Professor Christos H. Papadimitriou on how large language models anchor the meaning of abstract words. This collaboration led to the paper The Grounding Gap: How LLMs Anchor the Meaning of Abstract Concepts Differently from Humans.
Greece's national Artificial Intelligence competition for high-school students. I help design the competition tasks and mentor the students selected to represent Greece at the international competitions.