Tsutomu Yanagida is a Japanese physicist who first proposed the

seesaw mechanism In the theory of grand unification of particle physics, and, in particular, in theories of neutrino masses and neutrino oscillation, the seesaw mechanism is a generic model used to understand the relative sizes of observed neutrino masses, of the ...

in 1979 and developed the model of

leptogenesis __notoc__ In physical cosmology, leptogenesis is the generic term for hypothetical physical processes that produced an asymmetry between leptons and antileptons in the very early universe, resulting in the present-day dominance of leptons over ...

. The name of the seesaw mechanism was given by him in a Tokyo conference in 1981. In 1994, he predicted, together with M. Fukugita, the nonzero cosmological constant Λ = (3 ± 1 meV)⁴ four years prior to the observation in order to resolve the age discrepancy between the Universe and some old stars. Tsutomu Yanagida received a PhD in physics at

Hiroshima University is a Japanese national university located in Higashihiroshima and Hiroshima, Japan. Established in 1929, it was chartered as a university in 1949 following the merge of a number of national educational institutions. History Under the Nationa ...

in 1977. In 1979, he proposed the

, that explains the mass of

neutrino A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass ...

s by introduction heavy right-handed neutrinos. Together with M. Fukugita, he developed the model of leptogenesis that traces the

baryon asymmetry In physical cosmology, the baryon asymmetry problem, also known as the matter asymmetry problem or the matter–antimatter asymmetry problem, is the observed imbalance in baryonic matter (the type of matter experienced in everyday life) and antib ...

back to a

lepton In particle physics, a lepton is an elementary particle of half-integer spin ( spin ) that does not undergo strong interactions. Two main classes of leptons exist: charged leptons (also known as the electron-like leptons or muons), and neutr ...

asymmetry. Till 2019 he was professor at Kavli Institute for Physics and Mathematics of the Universe at

Tokyo University , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by ...

. Some of his students in Tokyo were

Yasunori Nomura Yasunori Nomura (born 1974) is a theoretical physicist working on particle physics, quantum gravity, and cosmology. He is a professor of physics at University of California, Berkeley, a senior faculty scientist at Lawrence Berkeley National Labor ...

, Junji Hisano and Takeo Moroi. In 2019, he was appointed professor at

Shanghai Jiao Tong University Shanghai Jiao Tong University (SJTU; ) is a public research university in Shanghai, China. The university is funded by the Ministry of Education of China. The university was established on April 8, 1896 as Nanyang Public School (南洋� ...

. His research includes theoretical

particle physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) an ...

string theory In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects called strings. String theory describes how these strings propagate through space and interac ...

and

cosmology Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount (lexicographer), Thomas Blount's ''Glossographia'', and in 1731 taken up in ...

. Yanagida works on super symmetry,

inflation In economics, inflation is an increase in the general price level of goods and services in an economy. When the general price level rises, each unit of currency buys fewer goods and services; consequently, inflation corresponds to a reductio ...

and the baryon asymmetry. He is corresponding member of the Academy of Sciences and Humanities in Hamburg. In 2017 he visited the Higgs Centre of Theoretical Physics at

Edinburgh University The University of Edinburgh ( sco, University o Edinburgh, gd, Oilthigh Dhùn Èideann; abbreviated as ''Edin.'' in post-nominals) is a public research university based in Edinburgh, Scotland. Granted a royal charter by King James VI in 1582 ...

as guest scientist.

Honours

* 2020: The Particle Physics Medal (Physical Society of Japan) *2014: Helmholtz International Fellow Award *2012: Youji Totsuka Prize *2011: Hertz LectureHertz Lectures
/ref> at DESY Hamburg *2003: Alexander von Humboldt Prize *1992:

Nishina Memorial Prize The is the oldest and most prestigious physics award in Japan. Information Since 1955, the Nishina Memorial Prize has been awarded annually by the Nishina Memorial Foundation. The Foundation was established to commemorate Yoshio Nishina, who w ...

*1989: Yukawa Memorial Prize

Publications (selection)

* * * * *

Books

* Masataka Fukugita, Tsutomu Yanagida: ''Physics of Neutrinos and Application to Astrophysics'', Springer, 2003

References

External links

Academic family
at academictree.org
Publications
at

INSPIRE-HEP INSPIRE-HEP is an open access digital library for the field of high energy physics (HEP). It is the successor of the Stanford Physics Information Retrieval System (SPIRES) database, the main literature database for high energy physics since the 1970 ...

Slides
about seesaw mechanismus and leptogenesis {{DEFAULTSORT:Yanagida, Tsutomu Living people Japanese physicists Hiroshima University alumni 1949 births