Marina Ratner

Russian mathematician (1938–2017)

Marina E. Ratner

Marina Ratner in 1988

Born| (1938-10-30)October 30, 1938

Moscow, Russian SFSR

Died| July 7, 2017(2017-07-07) (aged 78)

El Cerrito, California

Nationality| Russian
Alma mater| Moscow State University
Awards| Ostrowski Prize (1993)
Scientific career
Fields| Mathematics
Institutions| University of California, Berkeley
Thesis|  Geodesic Flows on Unit Tangent Bundles of Compact Surfaces of Negative Curvature  (1969)
Doctoral advisor| Yakov Sinai

Marina Evseevna Ratner (Russian: Мари́на Евсе́евна Ра́тнер; October 30, 1938 – July 7, 2017[1]) was a professor of mathematics at the University of California, Berkeley who worked in ergodic theory.[2] Around 1990, she proved a group of major theorems concerning unipotent flows on homogeneous spaces, known as Ratner's theorems.[3] Ratner was elected to the American Academy of Arts and Sciences in 1992,[4] awarded the Ostrowski Prize in 1993 and elected to the National Academy of Sciences the same year. In 1994, she was awarded the John J. Carty Award from the National Academy of Sciences.[5]

## Biographical information

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Ratner was born in Moscow, Russian SFSR to a Jewish family, where her father was a plant physiologist and her mother a chemist. Ratner's mother was fired from work in the 1940s for writing to her mother in Israel, then considered an enemy of the Soviet state. Ratner gained an interest in mathematics in her fifth grade. From 1956 to 1961, she studied mathematics and physics at Moscow State University. Here, she became interested in probability theory, inspired by A.N. Kolmogorov and his group.[6] After graduation, she spent four years working in Kolmogorov's applied statistics group. Following this, she returned to Moscow State university for graduate studies were under Yakov G. Sinai, also a student of Kolmogorov. She completed her PhD thesis, titled "Geodesic Flows on Unit Tangent Bundles of Compact Surfaces of Negative Curvature", in 1969.[7] In 1971 she emigrated from the Soviet Union to Israel and she taught at the Hebrew University from 1971 until 1975. She began to work with Rufus Bowen at Berkeley and later emigrated to the United States and became a professor of mathematics at Berkeley.[8] Her work included proofs of conjectures dealing with unipotent flows on quotients of Lie groups made by S. G. Dani and M. S. Raghunathan.[9] For this and other work, she won the John J. Carty Award for the Advancement of Science in 1994.[10] she became only the third woman plenary speaker at International Congress of Mathematicians in 1994.[6]

Marina Ratner died July 7, 2017, at the age of 78.[11]

## Selected publications

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* Ratner, Marina (1990). "Strict measure rigidity for unipotent subgroups of solvable groups". Inventiones Mathematicae. 101 (1): 449–482. Bibcode:1990InMat.101..449R. doi:10.1007/BF01231511. ISSN 0020-9910. S2CID 120179569.
* Ratner, Marina (1990). "On measure rigidity of unipotent subgroups of semisimple groups". Acta Mathematica. 165: 229–309. doi:10.1007/BF02391906. ISSN 0001-5962.
* Ratner, Marina (1995). "Interactions Between Ergodic Theory, Lie Groups, and Number Theory". Proceedings of the International Congress of Mathematicians. pp. 157–182. doi:10.1007/978-3-0348-9078-6_13. ISBN 978-3-0348-9897-3.

## References

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1. ^ "In Memoriam". Department of Mathematics at University of California Berkeley. Retrieved 2020-03-24.
2. ^ Larry Riddle. "Marina Ratner". agnesscott.edu. Retrieved 2020-03-24.
3. ^ Morris, Dave (2005). Ratner's theorems on unipotent flows (PDF). Chicago: University of Chicago Press. CiteSeerX 10.1.1.240.9520. ISBN 0-226-53983-0. OL 10192523M.
4. ^ "LIST OF ACTIVE MEMBERS BY CLASS" (PDF). American Academy of Arts and Sciences. October 27, 2016. Retrieved 2020-03-24.
5. ^ "John J. Carty Award for the Advancement of Science". National Academy of Sciences. Archived from the original on 29 December 2010. Retrieved 25 February 2011.
6. ^ a b "Marina Ratner biography". mathshistory.st-andrews.ac.uk. Retrieved 2019-02-09.
7. ^ Marina Ratner at the Mathematics Genealogy Project
8. ^ Hartsock, John (1987-12-03). "Soviet refusenik to be released". UPI.
9. ^ Cook, Mariana (2009). Mathematicians : an outer view of the inner world. Princeton, N.J: Princeton University Press. ISBN 978-0-691-13951-7. OL 23694032M.
10. ^ "John J. Carty Award for the Advancement of Science". nasonline.org. Retrieved 2019-02-09.
11. ^ Ng-Yu, Maya (2017-07-28). "Professor emeritus, acclaimed mathematician Marina Ratner dies at 78". The Daily Californian. Retrieved 2019-12-20.

Authority control databases: Academics |

* Mathematics Genealogy Project
* zbMATH
* MathSciNet

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