3 papers
math.CV2025
Indefinite structure of the Bergman kernel on the open unit disk
Kenta Kojin, Shuhei Kuwahara, Michio Seto
In this paper, we focus on an indefinite structure lying behind the Bergman kernel on the open unit disk. In particular, an invariant distance, birational maps and an indefinite ke…
math.FA2025
Isometric Gelfand transforms of complete Nevanlinna-Pick spaces
Kenta Kojin
We show that any complete Nevanlinna-Pick space whose multiplier algebra has isometric Gelfand transform (or commutative C*-envelope) is essentially the Hardy space on the open uni…
math.FA2024
An RKHS approach to the indefinite Schwarz-Pick inequality on the bidisk
Kenta Kojin
In this short note, we will give a generalization of the indefinite Schwarz-Pick inequality due to Seto [8]. Our approach is based on a connection between complex geometry and the…