Gheorghe Vrănceanu (June 30, 1900 – April 27, 1979) was a Romanian mathematician, best known for his work in

differential geometry and topology 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 single variable calculus, vector calculus, linear algebra and multil ...

. He was titular member of the Romanian Academy and vice-president of the

International Mathematical Union The International Mathematical Union (IMU) is an international organization devoted to international cooperation in the field of mathematics across the world. It is a member of the International Science Council (ISC) and supports the International ...

Biography

He was born in 1900 in Valea Hogei, then a village in

Vaslui County Vaslui County () is a county (județ) of Romania, in the historical region Western Moldavia, with the seat at Vaslui. Demographics In 2011, it had a population of 395,499 and the population density was 74/km2. * Romanians - over 98% * Romani ...

, now a component of Lipova commune, in

Bacău County Bacău County () is a county (județ) of Romania, in Western Moldavia, with its capital city at Bacău. It has one commune, Ghimeș-Făget, in Transylvania. Geography This county has a total area of . In the western part of the county there a ...

. He was the eldest of five children in his family. After attending primary school in his village and high school in

Vaslui Vaslui (), a city in eastern Romania, is the seat of Vaslui County, in the historical region of Western Moldavia. The city administers five villages: Bahnari, Brodoc, Moara Grecilor, Rediu, and Viișoara. History Archaeological surveys indicate t ...

, he went to study mathematics at the

University of Iași The Alexandru Ioan Cuza University (; acronym: UAIC) is a public university located in , Romania. Founded by an 1860 decree of Prince Alexandru Ioan Cuza, under whom the former was converted to a university, the University of , as it was named ...

in 1919. There, he took courses with , Vera Myller, ,

Victor Vâlcovici Victor Vâlcovici ( – 21 June 1970) was a Romanian mechanician and mathematician. Biography Born into a modest family in Galați, he graduated first in his class in 1904 from Nicolae Bălcescu National College, Nicolae Bălcescu High Sch ...

, and

Simion Stoilow Simion Stoilow or Stoilov ( – 4 April 1961) was a Romanian mathematician, creator of the Romanian school of complex analysis, and author of over 100 publications. Biography He was born in Bucharest, and grew up in Craiova. His father, Colonel S ...

. After graduating in 1922, he went in 1923 to the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 ...

, where he studied under

David Hilbert David Hilbert (; ; 23 January 1862 – 14 February 1943) was a German mathematician and philosopher of mathematics and one of the most influential mathematicians of his time. Hilbert discovered and developed a broad range of fundamental idea ...

. Thereafter, he went to the University of Rome, where he studied under

Tullio Levi-Civita Tullio Levi-Civita, (; ; 29 March 1873 – 29 December 1941) was an Italian mathematician, most famous for his work on absolute differential calculus ( tensor calculus) and its applications to the theory of relativity, but who also made signifi ...

, obtaining his doctorate on November 5, 1924, with thesis ''Sopra una teorema di Weierstrass e le sue applicazioni alla stabilità''. The thesis defense committee was composed of 11 faculty, and was headed by

Vito Volterra Vito Volterra (, ; 3 May 1860 – 11 October 1940) was an Italian mathematician and physicist, known for his contributions to Mathematical and theoretical biology, mathematical biology and Integral equation, integral equations, being one of the ...

. Vrănceanu returned to

Iași Iași ( , , ; also known by other #Etymology and names, alternative names), also referred to mostly historically as Jassy ( , ), is the Cities in Romania, third largest city in Romania and the seat of Iași County. Located in the historical ...

, where he was appointed a lecturer at the university. In 1927–1928, he was awarded a

Rockefeller Foundation The Rockefeller Foundation is an American private foundation and philanthropic medical research and arts funding organization based at 420 Fifth Avenue, New York City. The foundation was created by Standard Oil magnate John D. Rockefeller (" ...

scholarship to study in France and the United States, where he was in a contact with

Élie Cartan Élie Joseph Cartan (; 9 April 1869 – 6 May 1951) was an influential French mathematician who did fundamental work in the theory of Lie groups, differential systems (coordinate-free geometric formulation of PDEs), and differential geometry. He ...

and

Oswald Veblen Oswald Veblen (June 24, 1880 – August 10, 1960) was an American mathematician, geometer and topologist, whose work found application in atomic physics and the theory of relativity. He proved the Jordan curve theorem in 1905; while this was lo ...

. In 1929, he returned to Romania, and was appointed professor at the University of Cernăuți. In 1939, he moved to the

University of Bucharest The University of Bucharest (UB) () is a public university, public research university in Bucharest, Romania. It was founded in its current form on by a decree of Prince Alexandru Ioan Cuza to convert the former Princely Academy of Bucharest, P ...

, where he was appointed Head of the Geometry and Topology department in 1948, a position he held until his retirement in 1970. His doctoral students include Henri Moscovici and . Vrănceanu was elected to the

Romanian Academy The Romanian Academy ( ) is a cultural forum founded in Bucharest, Romania, in 1866. It covers the scientific, artistic and literary domains. The academy has 181 active members who are elected for life. According to its bylaws, the academy's ma ...

as a corresponding member in 1946, then as a full member in 1955. From 1964 he was president of the Mathematics Section of the Romanian Academy. Also from 1964, he was an editor of the journal '' Revue Roumaine de mathématiques pures et appliquées'', founded that year. At the

International Congress of Mathematicians The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU). The Fields Medals, the IMU Abacus Medal (known before ...

held in

Vancouver Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...

, Canada in 1974, he was elected vice-president of the

, a position he held from 1975 to 1978. He died in

Bucharest Bucharest ( , ; ) is the capital and largest city of Romania. The metropolis stands on the River Dâmbovița (river), Dâmbovița in south-eastern Romania. Its population is officially estimated at 1.76 million residents within a greater Buc ...

in 1979 of an

intestinal obstruction Bowel obstruction, also known as intestinal obstruction, is a mechanical or functional obstruction of the intestines which prevents the normal movement of the products of digestion. Either the small bowel or large bowel may be affected. Signs ...

and was buried at the city's

Bellu Cemetery Șerban Vodă Cemetery (commonly known as Bellu Cemetery) is the largest and most famous cemetery in Bucharest, Romania. It is located on a plot of land donated to the local administration by Baron Barbu Bellu. It has been in use since 1858. T ...

. A high school in

Bacău Bacău ( ; , ; ; ) is the main city in Bacău County, Romania. With a population of 136,087 (as of 2021 census), Bacău is the 14th largest city in Romania. The city is situated in the historical region of Moldavia, at the foothills of the ...

(Colegiul Național "Gheorghe Vrânceanu") is named after him, and so is a school in Lipova.

Research

During his career, Vrănceanu published over 300 articles in journals throughout the world. His work covers a whole range of modern

geometry Geometry (; ) is a branch of mathematics concerned with properties of space such as the distance, shape, size, and relative position of figures. Geometry is, along with arithmetic, one of the oldest branches of mathematics. A mathematician w ...

, from the classical theory of surfaces, to the notion of non- holonomic spaces, which he discovered. In 1928 he gave an invited talk at the

Bologna Bologna ( , , ; ; ) is the capital and largest city of the Emilia-Romagna region in northern Italy. It is the List of cities in Italy, seventh most populous city in Italy, with about 400,000 inhabitants and 150 different nationalities. Its M ...

, titled ''Parallelisme et courbure dans une variété non holonome''. In it, he introduced the notion of "non-holonomic manifolds," which are

smooth manifolds In mathematics, a differentiable manifold (also differential manifold) is a type of manifold that is locally similar enough to a vector space to allow one to apply calculus. Any manifold can be described by a collection of charts (atlas (topology ...

provided with a smooth distribution that is generally not

integrable In mathematics, integrability is a property of certain dynamical systems. While there are several distinct formal definitions, informally speaking, an integrable system is a dynamical system with sufficiently many conserved quantities, or first ...

Publications

* * * *

Notes

References

* {{DEFAULTSORT:Vranceanu, Gheorghe 1900 births 1979 deaths People from Bacău County Alexandru Ioan Cuza University alumni Sapienza University of Rome alumni 20th-century Romanian mathematicians Topologists Differential geometers Academic staff of Chernivtsi University Academic staff of the University of Bucharest Titular members of the Romanian Academy Members of the Romanian Academy of Sciences Romanian expatriates in Italy Romanian expatriates in the United States Romanian expatriates in Germany Deaths from bowel obstruction Burials at Bellu Cemetery