Valentin Franke

Valentin Franke
Born	(1926-02-16)16 February 1926
Died	31 January 2025(2025-01-31) (aged 98)
Nationality	Soviet, Russian
Alma mater	Leningrad State University
Known for	One of the authors of the FGKLS equation (Lindblad equation)
Scientific career
Fields	Theoretical physics
Institutions	Saint Petersburg State University
Doctoral advisor	Yury Novozhilov

Valentin Alfredovich Franke (Russian: Валенти́н Альфре́дович Фрáнке; 16 February 1926 – 31 January 2025) was a Soviet and Russian theoretical physicist and academic. A Doctor of Sciences, he was professor of the High Energy & Elementary Particle at the Physics Department of Saint Petersburg State University.

Background and early career

V. A. Franke graduated from Kyiv Polytechnic Institute in 1949. After that he was distributed to a power plant in Amur Oblast, Russian Far East. In 1954 he externally graduated from Leningrad State University and then worked in Institute of Labor Protection in Leningrad.[1]

In 1962 V. A. Franke joined the physical faculty of LSU. He obtained his PhD under the supervision of Yury Novozhilov in 1965 and was habilitated in 1984. He was a professor of High Energy & Elementary Particle Physics Department until his retirement in 2020.

Scientific and educational activity

Franke worked in the fields of elementary particle physics, quantum mechanics and theory of gravitation. He wrote more than 70 papers on these topics.

In 1976, Franke obtained the general form of the renowned master equation for the evolution of density matrix. This equation was derived independently and simultaneously by V. A. Franke,[2] G. Lindblad[3] and V. Gorini, A. Kossakowski and E. C. G. Sudarshan[4] (see [5][6]). FGKLS (Franke-Gorini-Kossakowski-Lindblad-Sudarshan) equation plays an important role in the description of open quantum systems and the quantum measurement theory. V. A. Franke himself considered this equation as a natural generalisation of standard quantum mechanics, whose validity has to be proven experimentally.[7]

From 1981, Franke and his colleagues have been working on the light front quantization of the Yang—Mills theory. This approach proves itself useful in non-perturbative description of quantum chromodynamics.[8]

After the death of his long-time friend and colleague, Yuri Yappa, V. A. Franke had completed and edited his unfinished monograph on the spinor theory.[9]

Death

Franke died on 31 January 2025, at the age of 98.[10]

References

1. "Valentin A. Franke".
2. Franke, V. A. (1976). "On the general form of the dynamical transformation of density matrices". Theoretical and Mathematical Physics. 27 (2): 406–413. doi:10.1007/BF01051230. ISSN 0040-5779. S2CID 123168620.
3. Lindblad, G. (1976). "On the generators of quantum dynamical semigroups". Communications in Mathematical Physics. 48 (2): 119–130. doi:10.1007/BF01608499. ISSN 0010-3616. S2CID 55220796.
4. Gorini, V.; Kossakowski, A.; Sudarshan, E. C. G. (1976). "Completely positive dynamical semigroups of N‐level systems". Journal of Mathematical Physics. 17 (5): 821. doi:10.1063/1.522979.
5. Chruściński, Dariusz; Pascazio, Saverio (2017). "A Brief History of the GKLS Equation". Open Systems & Information Dynamics. 24 (3): 1740001. arXiv:1710.05993. doi:10.1142/S1230161217400017. ISSN 1230-1612. S2CID 90357.
6. Andrianov, A A; Ioffe, M V; Novikov, O O (18 October 2019). "Supersymmetrization of the Franke–Gorini–Kossakowski–Lindblad–Sudarshan equation". Journal of Physics A: Mathematical and Theoretical. 52 (42): 425301. arXiv:1901.03848. doi:10.1088/1751-8121/ab4338. ISSN 1751-8113. S2CID 153312733.
7. Franke, V. A. (2006). Novozhilov, V. (ed.). "The foundations of quantum theory and its possible generalizations". Proceedings of the 15th International V. A. Fock School for Advances of Physics 2005. SPbU Publ. arXiv:2103.05374.
8. Bakker, B.L.G.; Bassetto, A.; Brodsky, S.J.; et al. (2014). "Light-front quantum chromodynamics". Nuclear Physics B - Proceedings Supplements. 251–252: 165–174. arXiv:1309.6333. Bibcode:2014NuPhS.251..165B. doi:10.1016/j.nuclphysbps.2014.05.004. S2CID 117029089.
9. Yappa, Yu. A. (2004). Franke, V. A. (ed.). An Introduction to Spinor Theory and Its Applications in Physics. Saint Petersburg: SPb State University Publ. ISBN 5-288-01951-7.
10. "Ушёл из жизни Валентин Альфредович Франке". hep.spbu.ru. 1 February 2025. Retrieved 1 February 2025.