Regular biography
SAKAI Hiroshi is a professor at the Graduate School of Mathematical Sciences, The University of Tokyo. His research focuses on Mathematical Logic and Set Theory, particularly Large Cardinal Axioms, Forcing Axioms, and their consequences in infinite combinatorics and cardinal arithmetic. He investigates expansions of ZFC, the standard axiom system of set theory, to address undecidable propositions such as the Continuum Hypothesis. His work includes contributions to stationary reflection principles, two cardinal tree properties, and the interplay between reflection principles and cardinal arithmetic. He is an active member of the Mathematical Society of Japan and the Association for Symbolic Logic, and serves as an editor of The Journal of Symbolic Logic.