Question: What field of study did Boris Galerkin and Jakow Trachtenberg both work in?

full_context: Document 1: Israel Gelfand: Israel Moiseevich Gelfand, also written Israïl Moyseyovich Gel'fand, or Izrail M. Gelfand (Yiddish: ישראל געלפֿאַנד‎ , Russian: Изра́иль Моисе́евич Гельфа́нд ; 2 September [O.S. 20 August] 1913 – 5 October 2009) was a prominent Soviet mathematician. He made significant contributions to many branches of mathematics, including group theory, representation theory and functional analysis. The recipient of many awards, including the Order of Lenin and the Wolf Prize, he was a Fellow of the Royal Society and professor at Moscow State University and, after immigrating to the United States shortly before his 76th birthday, at Rutgers University.
Document 2: Georgy Adelson-Velsky: Georgy Maximovich Adelson-Velsky (Russian: Гео́ргий Макси́мович Адельсо́н-Ве́льский ; name is sometimes transliterated as Georgii Adelson-Velskii) (8 January 1922 – 26 April 2014) was a Soviet and Israeli mathematician and computer scientist.
Document 3: Jakow Trachtenberg: Jakow Trachtenberg (17 June 1888 – 1953) was a Jewish mathematician who developed the mental calculation techniques called the Trachtenberg system.
Document 4: Jacob Bernoulli: Jacob Bernoulli (also known as James or Jacques; 6 January 1655 [O.S. 27 December 1654] – 16 August 1705) was one of the many prominent mathematicians in the Bernoulli family. He was an early proponent of Leibnizian calculus and had sided with Leibniz during the Leibniz–Newton calculus controversy. He is known for his numerous contributions to calculus, and along with his brother Johann, was one of the founders of the calculus of variations. He also discovered the fundamental mathematical constant e. However, his most important contribution was in the field of probability, where he derived the first version of the law of large numbers in his work "Ars Conjectandi".
Document 5: Trachtenberg system: The Trachtenberg system is a system of rapid mental calculation. The system consists of a number of readily memorized operations that allow one to perform arithmetic computations very quickly. It was developed by the Russian Jewish engineer Jakow Trachtenberg in order to keep his mind occupied while being held in a Nazi concentration camp.
Document 6: Grigori Perelman: Grigori Yakovlevich Perelman (Russian: Григо́рий Я́ковлевич Перельма́н ; ] ; born 13 June 1966) is a Russian mathematician. He made a contribution to Riemannian geometry and geometric topology.
Document 7: Gershgorin circle theorem: In mathematics, the Gershgorin circle theorem may be used to bound the spectrum of a square matrix. It was first published by the Soviet mathematician Semyon Aronovich Gershgorin in 1931. The spelling of S. A. Gershgorin's name has been transliterated in several different ways, including Geršgorin, Gerschgorin, Gershgorin, Hershhorn, and Hirschhorn.
Document 8: Mikhail Golant: Mikhail Borisovich Golant (Russian: Михаи́л Бори́сович Го́лант ; 3 February 1923 – 7 February 2001) was a Soviet and Russian scientist and engineer. Best known as a leader of Soviet design of backward-wave tubes, he was awarded the Lenin Prize, the USSR State Prize, and the State Prize of the Russian Federation. He worked with Nikolay Devyatkov on the application of EHF therapy.
Document 9: Boris Galerkin: Boris Grigoryevich Galerkin (Russian: Бори́с Григо́рьевич Галёркин , surname more accurately romanized as Galyorkin; 4 March [O.S. 20 February] 1871  – 12 July 1945), born in Polotsk, Vitebsk Governorate, Russian Empire, was a Jewish Soviet mathematician and an engineer.
Document 10: Hermann Minkowski: Hermann Minkowski ( ; ] ; 22 June 1864 – 12 January 1909) was a mathematician and professor at Königsberg, Zürich and Göttingen. He created and developed the geometry of numbers and used geometrical methods to solve problems in number theory, mathematical physics, and the theory of relativity.
Document 11: Semyon Aranovich Gershgorin: Semyon Aronovich Gershgorin (August 24, 1901 – May 30, 1933) was a Soviet (born in Pruzhany, Belarus, Russian Empire) mathematician. He began as a student at the Petrograd Technological Institute in 1923, became a Professor in 1930, and was given an appointment at the Leningrad Mechanical Engineering Institute in the same year. His contributions include the Gershgorin circle theorem.
Document 12: Jorge Luis Borges and mathematics: Jorge Luis Borges and mathematics concerns several modern mathematical concepts found in certain essays and short stories of Argentinian author Jorge Luis Borges (1899-1986), including concepts such as set theory, recursion, chaos theory, and infinite sequences, although Borges' strongest links to mathematics are through Georg Cantor's theory of infinite sets, outlined in "The Doctrine of Cycles" ("La doctrina de los ciclos"). Some of Borges' most popular works such as "The Library of Babel" ("La Biblioteca de Babel"), "The Garden of Forking Paths" ("El Jardín de Senderos que se Bifurcan"), "The Aleph" ("El Aleph"), an allusion to Cantor's use of the Hebrew letter aleph (formula_1) to denote cardinality of transfinite sets. and "The Approach to Al-Mu'tasim" ("El acercamiento a Almotásim") illustrate his use of mathematics.
Document 13: Mikhail Kravchuk: Mykhailo Pylypovych Kravchuk, also Krawtchouk (Ukrainian: Миха́йло Пили́пович Кравчу́к ) (September 27, 1892 – March 9, 1942), was a Soviet Ukrainian mathematician who, despite his early death, was the author of around 180 articles on mathematics.
Document 14: Boris Numerov: Boris Vasilyevich Numerov (Russian: Борис Васильевич Нумеров ; January 29, 1891—September 13, 1941) was a Russian astronomer, land-surveyor and geophysicist. Born in Novgorod and graduated from the St. Petersburg University in 1913, he created various astronomic and mineralogical instruments, as well as for various algorithms and methods that bear his name. He was a member of the Academy of Sciences, observer at Pulkovo from 1913–1915, astronomer at the observatory of the University of Leningrad from 1915 to 1925, and director of the Central Observatory of Geophysics (1926–27), and Professor at the University of Leningrad (1924–1937). He was also the founder and director of the "Institute for Theoretical Astronomy" in Leningrad.
Document 15: Joseph F. Traub: Joseph Frederick Traub (June 24, 1932 – August 24, 2015) was an American computer scientist. He was the Edwin Howard Armstrong Professor of Computer Science at Columbia University and External Professor at the Santa Fe Institute. He held positions at Bell Laboratories, University of Washington, Carnegie Mellon, and Columbia, as well as sabbatical positions at Stanford, Berkeley, Princeton, California Institute of Technology, and Technical University, Munich. Traub was the author or editor of ten monographs and some 120 papers in computer science, mathematics, physics, finance, and economics. In 1959 he began his work on optimal iteration theory culminating in his 1964 monograph, which is still in print. Subsequently he pioneered work with Henryk Woźniakowski on computational complexity applied to continuous scientific problems (information-based complexity). He collaborated in creating significant new algorithms including the Jenkins-Traub Algorithm for Polynomial Zeros, as well as the Kung-Traub, Shaw-Traub, and Brent-Traub algorithms. One of his research areas was continuous quantum computing. As of November 10, 2015, his works have been cited 8500 times, and he has an h-index of 35.
ground_truth: mathematician