KOMATSU, Keiichi

J-GLOBAL         Last updated: Mar 29, 2019 at 02:40
KOMATSU, Keiichi
Waseda University
Faculty of Science and Engineering School of Fundamental Science and Engineering
Job title
Research funding number

Research Areas



Faculty of Science and Engineering, Waseda University
Graduate School, Division of Science and Engineering, Tokyo Institute of Technology

Published Papers

Weber's class number problem in the cyclotomic Z_2-extension of Q Ⅱ
Keiichi Komatsu and Takashi Fukuda
J. Theor. Nombres Bordeaux   22 359-368   2010
On the Iwasawa lamda-invariant of the cyclotomic Z_2-extension of Q(sqrt{p})
Keiichi Komatsu and Takashi Fukuda
Math. Comp.   78 1797-1808   2009
Weber's class number problem in the cyclotomic Z2-extension of Q
Keiichi Komatsu and Takashi Fukuda
Experimental Math.   18 213-222   2009
Iwasawa lamda-invariants and Mordel-Weil ranks of abelian varieties with complex multiplication,
T.Fukuda,k.Komatsu and S.Yamagata
Acta Arithmetica   127 305-307   2007
On the Iwasawa lambda-invariant of the cyclotomic Z2-extension of a real quadratic field
Keiichi Komatsu and Takashi Fukuda
Tokyo J. Math.   28(1) 259-264   2005

Research Grants & Projects

On Weber's class number one problem
Project Year: Apr 2012 - Mar 2015
Let p be a prime number, B_p,∞ the cyclotomic Z_p-extension of the rational number field Q, B_p,n the n-th layer of B_p,∞/Q and h_p,n the class number of B_p,n. We obtained the following:Let p be a prime number which is not congruent to 1 or -1 mo...
Project Year: 2007 - 2009
We studied the Noether's Problem, which asks the rationality of the fixed field of the rational function field of several variables over a given field, with respect to a given finite subgroup G of the Cremona group. We solved this problem affirmat...
Project Year: 2004 - 2006
We construct certain algebraic integers αm as special values of two variable theta functions in the ray class field of a certain quartic field modulo 2m, and study a property of prime i deals which appear in αm in connection to the relationships b...
Project Year: 2003 - 2005
Thanks to the current Grant-in-Aid, we were able to organize seven research workshops inviting the most active mathematicians on this field, through which we had many discussions on our subjects.
This enabled us to make a considerable developments...
Project Year: 2001 - 2003
In 1976, Coates and Wiles gave large improvement to Birch-Swinnerton-Dyer conjecture for some elliptic curves with complex multiplication by using elliptic units in abelian extensions of imaginary quadratic fields. Main purpose of car investigatio...