Project/Area Number  09640220 
Research Category 
GrantinAid for Scientific Research (C)

Section  一般 
Research Field 
解析学

Research Institution  KEIO UNIVERSITY 
Principal Investigator 
NAKADA Hitoshi KEIO UNIVERSITY,FACULTY OF SCIENCE AND TECHNOLOGY,ASSOCIATE PROFESSOR, 理工学部, 助教授 (40118980)

CoInvestigator(Kenkyūbuntansha) 
MORITA Takehiko TOKYO INSTITUTE OF TECHNOLOGY,FACULTY OF SCIENCE,ASSISTANT PROFESSOR, 理学部, 助教授 (00192782)
YURI Michiko SAPPORO UNIVERSITY,FACULTY OF MANAGEMENT,PROFESSOR, 経営学部, 教授 (70174836)
鈴木 由紀 慶應義塾大学, 理工学部, 助手 (30286645)
MAEJIMA Makoto KEIO UNIVERSITY,FACULTY OF SCIENCE AND TECHNOLOGY,PROFESSOR, 理工学部, 教授 (90051846)
SHIOKAWA Iekata KEIO UNIVERSITY,FACULTY OF SCIENCE AND TECHNOLOGY,PROFESSOR, 理工学部, 教授 (00015835)
ITO Yuji KEIO UNIVERSITY,FACULTY OF SCIENCE AND TECHNOLOGY,PROFESSOR, 理工学部, 教授 (70011468)

Project Fiscal Year 
1997 – 1998

Project Status 
Completed(Fiscal Year 1998)

Budget Amount *help 
¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1998 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Fiscal Year 1997 : ¥1,700,000 (Direct Cost : ¥1,700,000)

Keywords  ERGODIC THEORY / NUMBER THEORETIC TRANSFORMATION / CONTINUED FRACTIONS / エルゴード理論 / 数論的変換 / 連分数 / 自然拡大 / 正規数 
Research Abstract 
1. Normal numbers of Number theoretic transformations We showed that the set of regular continued fraction normal numbers is identical with the set of the nearest integer continued fraction normal numbers. We also gave a definition of Bnormal numbers and showed that the set of those numbers includes the set of regular c.f. normal numbers. We appliied the proof of these results to the normal number problem proposed by F.Schweiger. We gave a negative answer on this problem. 2. We considered backward continued fractions transformations associated to Hecke groups and constructed their natural extensions. As a result, we gave characterizations of hyperbolic points and elliptic points of Hecke groups by the periodicity and the finiteness of the c.f. expansions. It turned out that these are natural generalizations of the backward continued fractions for real numbers. 3. We extended the notion of number theoretic transformations to nonarchimedian fields. First we consider continued fractions over the set of formal Laurent power seris with a finite field coefficients. Here the continued fraction digits are polynomials with the finite field coefficients. Next, we started to study fexpansion theory in this case and we will continue for some years on this problem. Main part of the project will be to study the theory of Fibered Systems for non archimedian fileds.
