Adolfas Pranaitis Jucys (12 September 1904 – 4 February 1974) (also referred to as ''Yutsis'', ''Yuzis'', or ''Ioucis'' depending on translation) was a

Lithuania Lithuania (; lt, Lietuva ), officially the Republic of Lithuania ( lt, Lietuvos Respublika, links=no ), is a country in the Baltic region of Europe. It is one of three Baltic states and lies on the eastern shore of the Baltic Sea. Lithuania ...

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experimen ...

and mathematician, and inducted member of the

Lithuanian Academy of Sciences The Lithuanian Academy of Sciences or LMA ( lt, Lietuvos mokslų akademija) is a state-funded independent organization in Lithuania dedicated for science and research. Its mission is to mobilize prominent scientists and initiate activities that ...

in 1953. He graduated from

Kaunas University Vytautas Magnus University (VMU) ( lt, Vytauto Didžiojo universitetas (VDU)) is a public university in Kaunas, Lithuania. The university was founded in 1922 during the Polish–Lithuanian War, interwar period as an alternate national university ...

in 1931 and later worked with both creators of the self-consistent field method –

Douglas Hartree Douglas Rayner Hartree (27 March 1897 – 12 February 1958) was an English mathematician and physicist most famous for the development of numerical analysis and its application to the Hartree–Fock equations of atomic physics and the c ...

in Manchester (in 1938) and

Vladimir Fock Vladimir Aleksandrovich Fock (or Fok; russian: Влади́мир Алекса́ндрович Фок) (December 22, 1898 – December 27, 1974) was a Soviet Union, Soviet physicist, who did foundational work on quantum mechanics and quantum ...

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 Vilnius University ( lt, Vilniaus universitetas) is a public research university, oldest in the Baltic states and in Northern Europe outside the United Kingdom (or 6th overall following foundations of Oxford, Cambridge, St. Andrews, Glasgow and ...

(1944–1971). He organized the first Institute of Physics and Mathematics in Lithuania and was its first director (1956–1963), and later (1971–1974) the head of the Institute's Department of Quantum Mechanical Calculations. Jucys developed the theory of the electronic structure of atoms, formulated in a general form the multiconfiguration Hartree–Fock equations taking into account the correlation effects. He along with his co-workers obtained the first solutions of such equations and applied them in atomic structure calculations, later introduced and developed the extended method of calculation, as well as using non-orthogonal radial orbitals. Adolfas Jucys with his students developed the mathematical apparatus of many-electron atoms with open shells. The most known work in this field is the monograph, in which the original graphical method for the quantities of the angular momentum theory was presented. In particular, Yutsis graphs (connected simple graphs which can be partitioned into two vertex-induced trees) are named after Adolfas Jucys. Adolfas Jucys had an interest in the

representation theory of Lie groups In mathematics and theoretical physics, a representation of a Lie group is a linear action of a Lie group on a vector space. Equivalently, a representation is a smooth homomorphism of the group into the group of invertible operators on the vec ...

of different rank, but the Jucys–Murphy elements in the group algebra

\mathbb_n

of the

symmetric group In abstract algebra, the symmetric group defined over any set is the group whose elements are all the bijections from the set to itself, and whose group operation is the composition of functions. In particular, the finite symmetric group \m ...

are named after his son

Algimantas Adolfas Jucys 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 ...

References

{{DEFAULTSORT:Jucys, Adolfas 1904 births 1974 deaths Vilnius University alumni Vilnius University faculty Lithuanian physicists 20th-century Lithuanian mathematicians Theoretical physicists Vytautas Magnus University alumni Soviet physicists Soviet mathematicians