Victor (Viktor) Abramovich Zalgaller ( he, ויקטור אבּרמוביץ' זלגלר; russian: Виктор Абрамович Залгаллер; 25 December 1920 – 2 October 2020) was a Russian-Israeli mathematician in the fields of

geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...

and

optimization Mathematical optimization (alternatively spelled ''optimisation'') or mathematical programming is the selection of a best element, with regard to some criterion, from some set of available alternatives. It is generally divided into two subfi ...

. He is best known for the results he achieved on

convex polyhedra A convex polytope is a special case of a polytope, having the additional property that it is also a convex set contained in the n-dimensional Euclidean space \mathbb^n. Most texts. use the term "polytope" for a bounded convex polytope, and the wo ...

linear Linearity is the property of a mathematical relationship (''function'') that can be graphically represented as a straight line. Linearity is closely related to '' proportionality''. Examples in physics include rectilinear motion, the linear r ...

and

dynamic programming Dynamic programming is both a mathematical optimization method and a computer programming method. The method was developed by Richard Bellman in the 1950s and has found applications in numerous fields, from aerospace engineering to economics. I ...

isoperimetry In mathematics, the isoperimetric inequality is a geometric inequality involving the perimeter of a set and its volume. In n-dimensional space \R^n the inequality lower bounds the surface area or perimeter \operatorname(S) of a set S\subset\R^n by ...

, and

differential geometry Differential geometry is a mathematical discipline that studies the geometry of smooth shapes and smooth spaces, otherwise known as smooth manifolds. It uses the techniques of differential calculus, integral calculus, linear algebra and multili ...

Biography

Zalgaller was born in

Parfino Parfino (russian: Па́рфино) is an urban locality (a work settlement) and the administrative center of Parfinsky District of Novgorod Oblast, Russia, located along the Lovat River, east of Staraya Russa. Municipally, it is incorporated ...

Novgorod Governorate Novgorod Governorate (Pre-reformed rus, Новгоро́дская губе́рнія, r=Novgorodskaya guberniya, p=ˈnofɡərətskəjə ɡʊˈbʲernʲɪjə, t=Government of Novgorod), was an administrative division (a '' guberniya'') of the Ru ...

on 25 December 1920. In 1936, he was one of the winners of the Leningrad Mathematics Olympiads for high school students. He started his studies at the

Leningrad State University Saint Petersburg State University (SPBU; russian: Санкт-Петербургский государственный университет) is a public research university in Saint Petersburg, Russia. Founded in 1724 by a decree of Peter the G ...

, however,

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

intervened in 1941, and Zalgaller joined the

Red Army The Workers' and Peasants' Red Army (Russian: Рабо́че-крестья́нская Кра́сная армия),) often shortened to the Red Army, was the army and air force of the Russian Soviet Federative Socialist Republic and, after ...

. He took part in the defence of

Leningrad Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...

, and in 1945 marched into Germany. He worked as a teacher at the

Saint Petersburg Lyceum 239 Presidential Physics and Mathematics Lyceum No. 239 (russian: link=no, Президентский физико-математический лицей №239), is a public Education in Russia#Secondary school, high school in Saint Petersburg, Rus ...

, and received his 1963 doctoral dissertation on polyhedra with the aid of his high school students who wrote the computer programs for the calculation. Zalgaller did his early work under direction of A. D. Alexandrov and

Leonid Kantorovich Leonid Vitalyevich Kantorovich ( rus, Леони́д Вита́льевич Канторо́вич, , p=lʲɪɐˈnʲit vʲɪˈtalʲjɪvʲɪtɕ kəntɐˈrovʲɪtɕ, a=Ru-Leonid_Vitaliyevich_Kantorovich.ogg; 19 January 19127 April 1986) was a Soviet ...

. He wrote joint

monographs A monograph is a specialist work of writing (in contrast to reference works) or exhibition on a single subject or an aspect of a subject, often by a single author or artist, and usually on a scholarly subject. In library cataloging, ''monograph ...

with both of them. His later monograph ''Geometric Inequalities'' (joint with Yu. Burago) is still the main reference in the field. Zalgaller lived in

Saint Petersburg Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...

most of his life, having studied and worked at the

and the

Steklov Institute of Mathematics Steklov Institute of Mathematics or Steklov Mathematical Institute (russian: Математический институт имени В.А.Стеклова) is a premier research institute based in Moscow, specialized in mathematics, and a part ...

(Saint Petersburg branch). In 1999, he immigrated to

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

. Zalgaller died on 2 October 2020 at the age of 99.

References

* V. A. Aleksandrov, et al. ''Viktor Abramovich Zalgaller (on his 80th birthday)'', Russian Mathematical Surveys, Vol. 56 (2001), 1013–1014 (se
here
for a Russian version). * Yu. D. Burago, et al. ''Viktor Abramovich Zalgaller (on his 80th birthday)'', J. Math. Sci. (N. Y.) J. Math. Sci. (N.Y.) Vol. 119 (2004), 129–132 (see tp://ftp.pdmi.ras.ru/pub/publicat/znsl/v280/p007.ps.gz herefor a Russian version). * M. Z. Solomyak, ''A few words about Viktor Abramovich Zalgaller'', J. Math. Sci. (N.Y.) Vol. 119 (2004), 138–140. *

S. S. Kutateladze S is the nineteenth letter of the English alphabet. S may also refer to: History * an Anglo-Saxon charter's number in Peter Sawyer's, catalogue Language and linguistics * Long s (ſ), a form of the lower-case letter s formerly used where "s ...

,
A Tribute to the Philanthropist and Geometer
'. * ''List of papers of V. A. Zalgaller'', available tp://ftp.pdmi.ras.ru/pub/publicat/znsl/v280/p014.ps.gz here(mostly in Russian). *

External links

*
Intrinsic Geometry of Surfaces
— book by A.D Alexandrov and V.A. Zalgaller (AMS Online Book, originally translated in 1967).

(in Russian).
Lecture read in 1999 in St.Petersburg, Russia
(video, in Russian) 1920 births 2020 deaths 20th-century Russian mathematicians 21st-century Russian mathematicians Differential geometers Israeli Jews Israeli mathematicians People from Parfinsky District Russian emigrants to Israel Russian Jews Saint Petersburg State University alumni Soviet mathematicians {{Russia-mathematician-stub