To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
Languages
Recent
Show all languages
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

From Wikipedia, the free encyclopedia

Aizik Isaakovich Vol'pert
Born(1923-06-05)5 June 1923[1][2]
DiedJanuary 2006 (2006-02) (aged 82)
Alma mater
Known for
Scientific career
Institutions

Aizik Isaakovich Vol'pert (Russian: Айзик Исаакович Вольперт) (5 June 1923[1][2] – January 2006) (the family name is also transliterated as Volpert[4] or Wolpert[5]) was a Soviet and Israeli mathematician and chemical engineer[6] working in partial differential equations, functions of bounded variation and chemical kinetics.

Life and academic career

The Programme Committee of the Russian Conference "Mathematical Methods in Chemical Kinetics", Shushenskoye, Krasnoyarsk Krai, 1980. From left to right: A.I. Volpert, V.I. Bykov, A.N. Gorban, G.S. Yablonsky, A.N.Ivanova.

Vol'pert graduated from Lviv University in 1951, earning the candidate of science degree and the docent title respectively in 1954 and 1956 from the same university:[1] from 1951 on he worked at the Lviv Industrial Forestry Institute.[1] In 1961 he became senior research fellow[7] while 1962 he earned the "doktor nauk"[2] degree from Moscow State University. In the 1970s–1980s A. I. Volpert became one of the leaders of the Russian Mathematical Chemistry scientific community.[8] He finally joined Technion’s Faculty of Mathematics in 1993,[3] doing his Aliyah in 1994.[9]

Work

Index theory and elliptic boundary problems

Vol'pert developed an effective algorithm for calculating the index of an elliptic problem before the Atiyah-Singer index theorem appeared:[10] He was also the first to show that the index of a singular matrix operator can be different from zero.[11]

Functions of bounded variation

He was one of the leading contributors to the theory of BV-functions: he introduced the concept of functional superposition, which enabled him to construct a calculus for such functions and applying it in the theory of partial differential equations.[12] Precisely, given a continuously differentiable function f : ℝp → ℝ and a function of bounded variation u(x) = (u1(x),...,up(x)) with x ∈ ℝn and n ≥ 1, he proves that fu(x) = f(u(x)) is again a function of bounded variation and the following chain rule formula holds:[13]

where f(u(x)) is the already cited functional superposition of f and u. By using his results, it is easy to prove that functions of bounded variation form an algebra of discontinuous functions: in particular, using his calculus for n = 1, it is possible to define the product H ⋅ δ of the Heaviside step function H(x) and the Dirac distribution δ(x) in one variable.[14]

Chemical kinetics

His work on chemical kinetics and chemical engineering led him to define and study differential equations on graphs.[15]

Selected publications

See also

Notes

  1. ^ a b c d See Kurosh et al. (1959b, p. 145).
  2. ^ a b c See Fomin & Shilov (1969, p. 265).
  3. ^ a b According to the few information given by the Editorial staff of Focus (2003, p. 9).
  4. ^ See Chuyko (2009, p. 79).
  5. ^ See Mikhlin & Prössdorf 1986, p. 369.
  6. ^ His training as an engineer is clearly indicated by Truesdell (1991, p. 88, footnote 1) who, referring to the book (Hudjaev & Vol'pert 1985), writes exactly:-"Be it noted that this clear, excellent, and compact book is written by and for engineers".
  7. ^ Precisely he became "старший научный сотрудник", abbreviated as "ст. науч. сотр.", according to Fomin & Shilov (1969, p. 265).
  8. ^ Manelis & Aldoshin (2005, pp. 7–8) detail briefly Vol'pert's and other scientists contribution to the development of mathematical chemistry. Precisely, they write that "В работах математического отдел института ( А. Я. Повзнер, А. И. Вольперт, А. Я. Дубовицкий) получили широкое развитие математической основи химической физики: теория систем дифференциальных уравнений, методы оптимизации, современные вычислительные методы методы отображения и т.д., которые легли в основу современной химической физики (теоретические основы химической кинетики, макрокинетики, теории горения и взрыва и т.д.)", i.e. (English translation) "In the Mathematical Department of the Institute (A. Ya. Povzner, A. I. Vol'pert, A. Ya. Dubovitskii) the mathematical foundations of chemical physics have been widely developed: particularly the theory of systems of differential equations, optimization techniques, advanced computational methods, imaging techniques, etc. which formed the basis of modern chemical physics (the theoretical foundations of chemical kinetics, macrokinetics, the theory of combustion and explosion, etc.)".
  9. ^ According to Ingbar (2010, p. 80).
  10. ^ According to Chuyko (2009, p. 79). See also Mikhlin (1965, pp. 185 and 207–208) and Mikhlin & Prössdorf 1986, p. 369.
  11. ^ See Mikhlin & Prössdorf 1986, p. 369 and also Prössdorf 1991, p. 108.
  12. ^ In the paper (Vol'pert 1967, pp. 246–247): see also the book (Hudjaev & Vol'pert 1985, Chapter 4, §6. "Differentiation formulas").
  13. ^ See the entry on functions of bounded variation for more details on the quantities appearing in this formula: here it is only worth to remark that a more general one, meaningful even for Lipschitz continuous functions f : ℝp → ℝs, has been proved by Luigi Ambrosio and Gianni Dal Maso in the paper (Ambrosio & Dal Maso 1990).
  14. ^ See Dal Maso, Lefloch & Murat (1995, pp. 483–484). This paper is one of several works where the results of the paper (Vol'pert 1967, pp. 246–247) are extended in order to define a particular product of distributions: the product introduced is called the "Nonconservative product".
  15. ^ See (Vol'pert 1972) and also (Hudjaev & Vol'pert 1985, pp. 607–666).

References

Biographical references

Scientific references

This page was last edited on 12 March 2024, at 12:16
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.