Ludvig Faddeev (born March 23, 1934, in Leningrad, USSR) is a Soviet and Russian theoretical physicist and mathematician, scientific expert, a member of the USSR Academy of Sciences (1976), later the Russian Academy of Sciences (RAS). Honorary Citizen of St. Petersburg (2010). President of the International Mathematical Union in 1987–1990.

#### Biography

The son of mathematicians, Corresponding member of the USSR Academy of Sciences Dmitry Faddeev (1907-1989) and Vera Faddeeva (nee Zamyatina, 1906–1983).

He finished the 155th boys school located in Smolninskiy district of Leningrad. Now it’s known as 155th gymnasium in the Central District of St. Petersburg. Faddeev attended the Faculty of Physics at Leningrad University, receiving his undergraduate degree in 1956. His doctoral work on scattering theory was completed in 1959 under the direction of Olga Ladyzhenskaya and Vladimir Fock. PhD in Physics and Mathematics (1959); his thesis was “The properties of the S-matrix for scattering on local potential.” Post-PhD degree in Physics and Mathematics (1963), defended his thesis on the research results in the field of quantum scattering theory for the three-particle system. His post-doctoral thesis made the basis of a new scientific field in quantum physics. He founded the world-famous mathematical physics research school.

Professor of the Leningrad (St. Petersburg) State University (1967). A fellow member (academician) of the USSR Academy of Sciences (1976).

He worked at the Leningrad Department of the Mathematical Institute of the USSR first as a junior, then as a senior research officer, and after that was the head of the Mathematical Problems of Physics Laboratory. In the 1960s he prelected to the students of the Faculty of Mathematics and Mechanics upon quantum mechanics. Faddeev was the head of the St. Petersburg Department of Steklov Institute of Mathematics, Russian Academy of Sciences (PDMI RAS) from 1976 to 2000. He founded the Euler International Mathematical Institute, now a department of PDMI RAS, in 1988–1992. He held a position of the vice-president of the International Mathematical Union in 1983-1986, and in 1987-1990 became its President. At the same time, he headed the Higher Mathematics and Mathematical Physics Department of the Physical Faculty in Leningrad (St. Petersburg) State University (until 2001), hereafter was a professor of this Department. Ludvig Faddeev is a member of the Presidium of RAS and the St. Petersburg Scientific Centre of RAS. Also, he is an Academician-Secretary of the Department of Mathematical Sciences of RAS. He was the chairman of the Commission for medals and named prizes awarded by the Russian Academy of Sciences till 2016. He is a chief editor of the Functional Analysis and its Applications. He also was an editor-in-chief of the Nature magazine and a part of the first editorial board of the Theoretical and Mathematical Physics magazine. He is a member of editorial boards of the “Journal of Mathematical Physics”, the “Letters in Mathematical Physics”, the “Journal of Functional Analysis”, the “Reviews in Mathematical Physics”, the “Annals of Physics” and others.

Ludvig Faddeev said his teachers were Vladimir Fock and Olga Ladyzhenskaya (from the speech at the awarding of the Russian Federation State Prize in 2004).

Married to Anna Veselova, a theoretical physicist, has two daughters (Elena, a mathematician, and Maria, a theoretical physicist), four grandchildren and four great-grandchildren.

#### Scientific research

He has made a fundamental contribution to the solution of the three-body problem in quantum mechanics (Faddeev equations); the inverse scattering problem for the Schrödinger equation in three-dimensional case;, in the quantization of non-Abelian gauge fields by the path-integral (Faddeev-Popov ghosts, together with Victor Popov); the creation of the quantum theory of solitons and quantum inverse scattering method in the development of the theory of quantum groups. He has published five books and over 200 scientific papers. At the 23th International Conference on the quantum theory of several particles on August 11, 2016, it was decided to establish the International Ludvig Faddeev medal.

#### Monographs

- Faddeev L. D., Slavnov A. A. Gauge fields: Introduction to quantum theory. Reading: Benjamin/Cummings Publ., 1980. 232 p.
- Faddeev L. D., Merkuriev S. P. Quantum scattering theory for several particle systems. Dordrecht: Kluwer Academic Publ. 1993. 404 p.
- Faddeev L. D., 40 years in mathematical physics. Singapore: World Scientific Publ., 1995. 471 p.
- Faddeev L. D., Yakubovskii O. A. Lectures on quantum mechanics for mathematics students. American Mathematical Society, 2009. 234 p.

#### Selected articles

- Berezin F. A., Faddeev L. D. Remark on the Schroedinger equation with singular potential // Soviet Math. Doklady. 1961. Vol. 2. P. 372–375.
- Faddeev L. D. Integral equations for the N-particle scattering problem // The physics of electronic and atomic collisions: Collected papers. Leningrad, 1967. P. 145–149.
- Faddeev L. D. Expansion in eigenfunctions of the Laplace operator on the fundamental domain of a discrete group on the Lobachevsky plane // Transl. Moscow Math. Soc. 1969. Vol. 17. P. 357–386.
- Zakharov V. E., Faddeev L. D. Korteweg—de Vries equation: A completely integrable Hamiltonian system // Funct. Anal. Appl. 1971. Vol. 5. P. 280–287.
- Popov V. N., Faddeev L. D. Perturbation theory for gauge invariant field. Preprint NAL-THY-57. 1972. 36 p.
- Korepin V. E., Faddeev L. D. Quantization of solitons // Theor. Math. Phys. 1975. Vol. 25. P. 1039–1049.
- Faddeev L. D. Operator anomaly for the Gauss law. Physics Letters B. 1984. v. 145. pp. 81-84.
- Faddeev L. D., Shatashvili S. L. Realization of the Schwinger term in the Gauss law and the possibility of correct quantization of a theory with anomalies. Physics Letters B. 1986. v. 167. pp. 225–228.
- Faddeev L. D., Jackiw R. Hamiltonian reduction of unconstrained and constrained systems. Physical Review Letters. 1988. v. 60. pp. 1692–1694.
- Reshetikhin N. Yu., Takhtajan L. A., Faddeev L. D. Quantization of Lie groups and Lie algebras // Leningrad Math. J. 1990. Vol. 1. P. 193–225.
- Faddeev L. D., Niemi A. J. Partially dual variables in SU(2) Yang—Mills theory // Phys. Rev. Lett. 1999. Vol. 82. P. 1624–1627.

#### Social activity

Elected official of the Leningrad City Council (1977–1987).

He ran for deputies of the USSR in 1989.

Like many math academics never was in the Communist Party.

#### Awards

USSR State Prize (1971)

Dannie Heineman Prize for Mathematical Physics (1974)

Order of the Red Banner of Labour (1981)

Order of Lenin (1987)

Dirac Prize (1990)

Order of Friendship of Peoples (1994)

Russian Federation State Prizes (1995)

A. P. Karpinsky Prize (1995)

Max Planck Medal (1996)

Order for Merit to the Fatherland, 4th class (1999)

Demidov Prize (2002)

Pomeranchuk Prize (2002)

Order for Merit to the Fatherland, 3rd class (2004)

Russian Federation State Prize (2005)

Henri Poincare Prize (2006)

Shaw Prize (2008)

Order of Honour (2010)

Honorary citizen of St. Petersburg (2010)

Lomonosov Gold Medal (2014)

Order of Friendship (2014)

Ludvig Faddeev medal (August 2016) — on the 23rd European Conference on Few-Body Problems in Physics in Denmark it was decided to establish the International Ludvig Faddeev medal. This decision was dated to the 55th anniversary of the publication of the article “Scattering theory for a three-particle system” (Soviet Physics JETP 12, 1960, 1014-1019.)

#### Honorable memberships

Foreign honorary member of the American Academy of Arts and Sciences, 1979

Foreign member the Polish Academy of Sciences, 1986

Honorary Doctor of the Nankai University, 1987

Honorary member of the Finnish Academy of Science and Letters, 1988

Honorary Doctor University of Buenos Aires, 1988

Foreign member of the Royal Swedish Academy of Sciences, 1989

Member of Academia Europaea, 1989

Foreign member of the National Academy of Sciences, USA, 1990

Honorary Doctor of the Uppsala University, 1993

Foreign member of the French Academy of Sciences, 2002

Foreign member of the Brazilian Academy of Sciences, 2004

Foreign member of the Chinese Academy of Sciences, 2008

Foreign member of the Royal Society, Great Britain, 2010

Foreign member of the Royal Society, Great Britain, 2010

Foreign member of the Bulgarian Academy of Sciences, 2013

Honorary Doctor of the University of Paris

Foreign honorary member of the Austrian Academy of Sciences