Yoshichika Iizuka, Yutaka Konomi, Shin Nakano. An Application of the Arithmetic of Elliptic Curves to the Class Number Problem for Quadratic Fields. TOKYO JOURNAL OF MATHEMATICS. 2021. 44. 1. 33-47
Yutaka Konomi, Takayuki Morisawa. On the class semigroup of the cyclotomic $\mathbb Z_p$-extension of the rational numbers. Journal of Commutative Algebra. 2019. 11. 1
Yutaka Konomi. On the $p$-rank of the ideal class group of a normal extension with simple Galois group. JOURNAL DE THEORIE DES NOMBRES DE BORDEAUX. 2019. 31. 3. 671-678