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Kenkichi Iwasawa

Kenkichi Iwasawa is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Kenkichi Iwasawa rather than just read about it. In short: Kenkichi Iwasawa (岩澤 健吉 Iwasawa Kenkichi, September 11, 1917 – October 26, 1998) was a Japanese mathematician who is known for his influence on algebraic number theory. Biography Iwasawa was born in Shinshuku-mura, a town near Kiryū, in Gunma Prefecture.

Key takeaways

  • Kenkichi Iwasawa belongs to mathematics; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Kenkichi Iwasawa to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Kenkichi Iwasawa from memory before moving on to harder problems.

Reference excerpt

Kenkichi Iwasawa (岩澤 健吉 Iwasawa Kenkichi, September 11, 1917 – October 26, 1998) was a Japanese mathematician who is known for his influence on algebraic number theory.

Biography Iwasawa was born in Shinshuku-mura, a town near Kiryū, in Gunma Prefecture. He attended elementary school there, but later moved to Tokyo to attend Musashi High School. From 1937 to 1940 Iwasawa studied as an undergraduate at the University of Tokyo, after which he entered graduate school at the same institution and became an assistant in the Department of Mathematics. In 1945 he was awarded a Doctor of Science degree. However, this same year Iwasawa became sick with pleurisy, and was unable to return to his position at the university until April 1947. From 1949 to 1955 he worked as assistant professor at the University of Tokyo. In 1950, Iwasawa was invited to Cambridge, Massachusetts to give a lecture at the International Congress of Mathematicians on his method to study Dedekind zeta functions using integration over ideles and duality of adeles; this method was also independently obtained by John Tate and is sometimes called Iwasawa–Tate theory. Iwasawa spent the next two years at the Institute for Advanced Study in Princeton, and in Spring of 1952 was offered a job at the Massachusetts Institute of Technology, where he worked until 1967. From 1967 until his retirement in 1986, Iwasawa served as Professor of Mathematics at Princeton. He returned to Tokyo with his wife in 1987. Among Iwasawa's most famous students are Robert F. Coleman, Bruce Ferrero, Ralph Greenberg, Gustave Solomon, Larry Washington, and Eugene M. Luks.

Research Iwasawa is known for introducing what is now called Iwasawa theory, which developed from researches on cyclotomic fields from the later 1950s. Before that he worked on Lie groups and Lie algebras, introducing the general Iwasawa decomposition.

List of books available in English Lectures on p-adic L-functions / by Kenkichi Iwasawa (1972) Local class field theory / Kenkichi Iwasawa (1986) ISBN 0-19-504030-9 Algebraic functions / Kenkichi Iwasawa; translated by Goro Kato (1993) ISBN 0-8218-4595-0 Iwasawa, Kenkichi (2001), Satake, Ichiro; Fujisaki, Genjiro; Kato, Kazuya; Kurihara, Masato; Nakajima, Shoichi; Coates, John (eds.), Collected papers. Vol. I, II, Berlin, New York: Springer-Verlag, ISBN 978-4-431-70314-3, MR 1851503

See also Iwasawa group Anabelian geometry Fermat's Last Theorem

References

Sources Coates, John (1999), "Kenkichi Iwasawa (1917--1998)", Notices of the American Mathematical Society, 46 (10): 1221–1225, MR 1715578, Zbl 1194.01081 O'Connor, John J.; Robertson, Edmund F., "Kenkichi Iwasawa", MacTutor History of Mathematics Archive, University of St Andrews

External links Kenkichi Iwasawa at the Mathematics Genealogy Project

Worked examples

Example 1 — a first encounter with Kenkichi Iwasawa

Start with the simplest possible case. Write down what Kenkichi Iwasawa claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Kenkichi Iwasawa before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Kenkichi Iwasawa ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Kenkichi Iwasawa

In research
Kenkichi Iwasawa appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Kenkichi Iwasawa in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Kenkichi Iwasawa is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1917 births, 1998 deaths, 20th-century Japanese mathematicians, so understanding it makes those chapters shorter.
In everyday life
Look for Kenkichi Iwasawa outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Kenkichi Iwasawa in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Kenkichi Iwasawa means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Kenkichi Iwasawa out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kenkichi Iwasawa in simple terms?

Kenkichi Iwasawa (岩澤 健吉 Iwasawa Kenkichi, September 11, 1917 – October 26, 1998) was a Japanese mathematician who is known for his influence on algebraic number theory. Biography Iwasawa was born in Shinshuku-mura, a town near Kiryū, in Gunma Prefecture.

Why does Kenkichi Iwasawa matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Kenkichi Iwasawa?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Kenkichi Iwasawa.

Tags

  • 1917 births
  • 1998 deaths
  • 20th-century Japanese mathematicians
  • Institute for Advanced Study visiting scholars
  • Massachusetts Institute of Technology faculty
  • Number theorists
  • Princeton University faculty
  • Scientists from Gunma Prefecture
  • University of Tokyo alumni

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