Gurgen SAHAKIAN (1913-2000)

 

Armenian outstanding physicist-theorist and astrophysicist, academician Gurgen Sahakian is one of the rare scientists who had a significant contribution in different fields of physics and astrophysics.

 

Gurgen Serob Sahakian was born on September 10, 1913 in Sogyutlu village (at present Sarnaghbyur village, in Shirak region of the Republic of Armenia). In 1939 he graduated from the Yerevan State University. He took part in the Great Patriotic War (1941-1945). Since 1939 he has worked at Yerevan State University, in 1951-1985 he was the Head of the Chair of Theoretical Physics of the same university, in 1967-1972 he was simultaneously the Dean of the Department of Physics. He also worked at the Yerevan Institute of Physics in 1959-1962, and in 1962-1970 at the Byurakan Astrophysical Observatory. In 1963 Gurgen Sahakian was honored with a doctorate of physical-mathematical sciences, In 1964 he was awarded a professorship, in 1970 he became an Honorary Figure of Science and Engineering of the Armenian SSR, and in 1982, an academician of the Academy of Sciences of the Republic of Armenia.

 

Sahakian’s works refer to the physics of elementary particles and cosmic rays, physics of degenerate superdense plasma and superdense stars, to the theory of gravity. He introduced the concept of formfactor of nucleons, investigated the distribution of charges in the nucleus, displayed that the elastic dispersion of electrons in large angles allows researching the inner structure of nucleons. At the beginning of 1960s due to Sahakian and Viktor Ambartsumian’s team works a new direction in astrophysics, the physics of superdense stars, was created. They have proved that in case of nuclear and larger densities the matter is a gas consisting of elementary particles where the baryons numerically predominate, and they have compiled models of superdense stellar forms of existence. They have also revealed a new phenomenon of general theory of relativity; the anomalous deficiency of mass. These results have a significant importance for the cosmogony of superdense celestial bodies. In his further works Sahakian displayed that dense plasma ring magnetosphere can be formed around rotating neutron stars, the outer edge of which can be a resource of cosmic radiation of high energy. In the researches concerning the generalized theory of gravity he assumed that the constant of cosmic gravity is a slowly shifting magnitude, and investigated the cosmogonical effects connected with that shift. Sahakian foresaw the existence of p-mesons in the isobars of heavy nuclei of small serial number, worked out a consistent theory of degenerate plasma in case of nuclear and larger or smaller densities and deduced the equation of the state of degenerate stellar matter. Instead of the formerly assumed neutronization effect he confirmed the pionization effect, as well as the state from the electronuclear plasma to general nuclear matter (accompanied by a jump of about 500 times density), the existence of phase transition. Sahakian has a great contribution in the development of theoretical physics and in the training of scientific personnel in the Republic of Armenia. He was awarded an Honorary Letter of the Presidium of the Armenian SSR Academy of Sciences (1976), orders of Red Star and People's Friendship. Sahakian's contribution is great in the training of Armenian physicists. Numerous highly talented physicists of Armenia were Sahakian's pupils. He is the author of a number of textbooks and monographs: “Equilibrium configurations of degenerate gas masses” (Ðàâíîâåñíûå êîíôèãóðàöèè âûðîæäåííûõ ãàçîâûõ ìàññ, Ì., 1972); “Quantum Mechanics” ( Êâàíòîâàÿ ìåõàíèêà, Å., 1982, co-author E.V. Chubarian); ‘Space-time and gravity” (Ïðîñòðàíñòâî – âðåìÿ è ãðàâèòàöèÿ, Å., 1985); "Physics of Neutron Stars" (Ôèçèêà íåéòðîííûõ çâåçä, Å., 1998).

 

Gurgen Sahakian passed away on March 26, 2000 in Yerevan.