Vadym Movsesovich Adamyan (Armenian: Վադիմ Մովսեսի Ադամյան ; Ukrainian: Вадим Мовсесович Адамян ; born 2 December 1938) is a Soviet and Ukrainian mathematician and theoretical physicist, professor and head of the Department of Theoretical Physics at Odessa University.
 He is known for his contributions to operator theory and functional analysis.
Algimantas Adolfas Jucys (14 November 1936 – 29 July 1997) was a Lithuanian theoretical physicist more prominent as a mathematician, a son of Lithuanian physicist Adolfas Jucys.
 Since 1967 Algis Jucys was researcher at the Institute of Physics and Mathematics of Lithuanian Academy of Sciences, in 1977-1990 at the Institute of Physics and in 1990-1996 at the Institute of Theoretical Physics and Astronomy, Lithuania.
Aleksander Ilyich Akhiezer (Russian: Алекса́ндр Ильи́ч Ахие́зер ; October 31, 1911 – May 4, 2000) was a Soviet theoretical physicist, known for contributions to numerous branches of theoretical physics, including quantum electrodynamics, nuclear physics, solid state physics, quantum field theory, and the theory of plasma.
 He was the brother of the mathematician Naum Akhiezer.
Hermann Klaus Hugo Weyl, {'1': ", '2': ", '3': 'ForMemRS', '4': "} (] ; 9 November 1885 – 8 December 1955) was a German mathematician, theoretical physicist and philosopher.
 Although much of his working life was spent in Zürich, Switzerland and then Princeton, he is associated with the University of Göttingen tradition of mathematics, represented by David Hilbert and Hermann Minkowski.
Edward Hutchinson Synge (1 June 1890 – 26 May 1957) was an Irish physicist who published a complete theoretical description of the near-field scanning optical microscope, an instrument used in nanotechnology, several decades before it was experimentally developed.
 He never completed university yet did significant original research in both microscopy and telescopy.
 He was the first to apply the principle of scanning in imaging, which later became important in a wide range of technologies including television, radar, and scanning electron microscopy.
 He was the older brother of distinguished mathematician and theoretical physicist John Lighton Synge.
Jules Henri Poincaré (] ; 29 April 1854 – 17 July 1912) was a French mathematician, theoretical physicist, engineer, and philosopher of science.
 He is often described as a polymath, and in mathematics as "The Last Universalist" by Eric Temple Bell, since he excelled in all fields of the discipline as it existed during his lifetime.
In mathematics, the unitarian trick is a device in the representation theory of Lie groups, introduced by for the special linear group and by Hermann Weyl for general semisimple groups.
 It applies to show that the representation theory of some group "G" is in a qualitative way controlled by that of some other compact group "K".
 An important example is that in which "G" is the complex general linear group, and "K" the unitary group acting on vectors of the same size.
 From the fact that the representations of "K" are completely reducible, the same is concluded for those of "G", at least in finite dimensions.
The Bogoliubov Prize is an award offered by the National Academy of Sciences of Ukraine for scientists with outstanding contribution to theoretical physics and applied mathematics.
The award is issued in the memory of theoretical physicist and mathematician Nikolay Bogoliubov.
Thomas Hill (January 7, 1818 – November 21, 1891) was an American Unitarian clergyman, mathematician, scientist, philosopher, and educator.
 Taught to read at an early age, Hill read voraciously and was well regarded for his capacious and accurate memory.
 His father taught him botany, and he took a delight in nature and devised scientific instruments, one of calculated eclipses and was subsequently awarded the Scott Medal by the Franklin Institute.
 Though not formally educated in his youth, Hill briefly attended the Lower Dublin Academy in Holmesburg, Pennsylvania and the Leicester Academy in Massachusetts, now the Leicester campus of Becker College, leaving in 1837.
 He earned his A.B. and D.Div.
 from Harvard University in 1843 and 1845 respectively.
 He was later made an honorary member of the Hasty Pudding.
 Hill was president of Antioch College from 1860 to 1862 until the Civil War forced the college to shut down; he then held the presidency of Harvard University from 1862 to 1868.
 Ill health caused his retirement from Harvard, and from 1873, he was head of the Unitarian parish in Portland, Maine.
Adolfas Pranaitis Jucys (12 September 1904 – 4 February 1974) (also referred to as "Yutsis", "Yuzis", or "Ioucis" depending on translation) was a Lithuanian theoretical physicist and mathematician, member of the Lithuanian Academy of Sciences in 1953.
 He graduated from Kaunas University in 1931 and later worked with both creators of the self-consistent field method – Douglas Hartree in Manchester (in 1938) and Vladimir Fock in Leningrad (1949–1951).
 Adolfas Jucys created the scientific school of theoretical physics in Vilnius, was the head of the Department of Theoretical Physics at Vilnius University (1944–1971).
 He organized the first Institute of Physics and Mathematics in Lithuania and was its first director (1956–1963), later (1971–1974) the head of the Department of Quantum Mechanical Calculations of the Institute.

Question: What is the nationality of this mathematician, theoretical physicist and philosopher who contributed to the unitarian trick?
Answer: German