- Sin-Itiro Tomonaga
Infobox Scientist

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name = Sin-Itiro Tomonaga (朝永 振一郎)

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birth_date = Birth date|1906|3|31

birth_place =Tokyo ,Japan

death_date = Death date and age|1979|7|8|1906|3|31

death_place = Tokyo, Japan

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fields =Theoretical physics

workplaces =Institute for Advanced Study

Tokyo University of Education

alma_mater = Kyoto Imperial University

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known_for =Quantum electrodynamics

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awards =Nobel Prize in Physics (1965)

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footnotes =**Sin-Itiro Tomonaga**or**Shinichirō Tomonaga**(朝永 振一郎 "Tomonaga Shin'ichirō",March 31 ,1906 –July 8 ,1979 ) was aJapan esephysicist , influential in the development ofquantum electrodynamics , work for which he was jointly awarded theNobel Prize in Physics in 1965 along withRichard Feynman andJulian Schwinger .**Biography**Tomonoga was born in

Tokyo in 1906. He was the second child and eldest boy of a Japanese philosopher,Sanjūrō Tomonaga . He entered the Kyoto Imperial University in 1926.Hideki Yukawa , also aNobel Prize winner, was one of his classmates duringundergraduate school. During graduate school at the same university, he worked as an assistant in the university for three years. After graduate school, he joined Nishina's group inRiken . In 1937, while working in Leipzig, he collaborated with the research group ofWerner Heisenberg . Two years later, he returned to Japan due to the outbreak of theSecond World War , but finished his doctoral degree on the study of nuclear materials with his thesis on work he had done while in Leipzig.In Japan, he was appointed to a professorship in the Tokyo University of Education (a forerunner of

Tsukuba University ). During the war he studied themagnetron ,meson theory, and his "super-many-time" theory. In 1948, he and his students re-examined a 1939 paper bySidney Dancoff that attempted, but failed, to show that the infinite quantities that arise in QED can be canceled with each other. Tomonaga applied his super-many-time theory and a relativistic method based on the non-relativistic method ofWolfgang Pauli and Fierz to greatly speed up and clarify the calculations. Then he and his students found that Dancoff had overlooked one term in the perturbation series. With this term, the theory gave finite results; thus Tomonaga discovered therenormalization method independently ofJulian Schwinger and calculated physical quantities such as theLamb shift at the same time.In the next year, he was invited by

Robert Oppenheimer to work at theInstitute for Advanced Study in Princeton Township. He studied amany-body problem on the collective oscillations of a quantum-mechanical system. In the following year, he returned to Japan and proposed theTomonaga-Luttinger liquid . In 1965, he was awarded theNobel Prize in Physics , withJulian Schwinger andRichard P. Feynman , for the study of QED, specifically for the discovery of therenormalization method. He died inTokyo in 1979.**References***Schweber, Sylvan S., 1994. "QED and the men who made it : Dyson, Feynman, Schwinger, and Tomonaga". Princeton Univ. Press.

* [*http://nobelprize.org/nobel_prizes/physics/laureates/1965/tomonaga-lecture.html Tomonaga's Nobel Prize Lecture*]**External links*** [

*http://www.nobel.se/physics/laureates/1965/tomonaga-bio.html Nobel Prize biography*]

* [*http://physics.nobel.brainparad.com/shinitiro_tomonaga.html Shinichiro Tomonaga*]

* [*http://holiker.narod.ru/five/tomonaga-lecture.html fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles.*]

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