Ljubomir Chakaloff (or Lubomir Nikolov Chakalov) was a

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedon ...

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

. He was born in 1886 in

Samokov Samokov ( bg, Самоков ) is a town in Sofia Province in the southwest of Bulgaria. It is situated in a basin between the mountains Rila and Vitosha, 55 kilometres from the capital Sofia. Due to the suitable winter sports conditions, Sam ...

and died in 1963 at the age of 77. He was unmarried at the time of his death. He graduated from

Sofia University Sofia University, "St. Kliment Ohridski" at the University of Sofia, ( bg, Софийски университет „Св. Климент Охридски“, ''Sofijski universitet „Sv. Kliment Ohridski“'') is the oldest higher education i ...

in June 1908, with an honors degree in mathematics and physics. In 1925, he received a doctoral degree in mathematics from the

University of Naples The University of Naples Federico II ( it, Università degli Studi di Napoli Federico II) is a public university in Naples, Italy. Founded in 1224, it is the oldest public non-sectarian university in the world, and is now organized into 26 depar ...

defending a thesis (''Le equazioni di Riccati'') about

Riccati equation In mathematics, a Riccati equation in the narrowest sense is any first-order ordinary differential equation that is quadratic in the unknown function. In other words, it is an equation of the form : y'(x) = q_0(x) + q_1(x) \, y(x) + q_2(x) \, y^2(x ...

s, having as advisor

Ernesto Pascal Ernesto Pascal (1865–1940) was an Italian mathematician. Life and work Pascal graduated in mathematics from the university of Naples in 1887. In the following two years he attended courses in the universities of Pisa and Göttingen; in the l ...

. His main contributions are in the areas of real and complex analysis,

number theory Number theory (or arithmetic or higher arithmetic in older usage) is a branch of pure mathematics devoted primarily to the study of the integers and arithmetic function, integer-valued functions. German mathematician Carl Friedrich Gauss (1777� ...

differential equations In mathematics, a differential equation is an equation that relates one or more unknown functions and their derivatives. In applications, the functions generally represent physical quantities, the derivatives represent their rates of change, an ...

elementary mathematics Elementary mathematics consists of mathematics topics frequently taught at the primary or secondary school levels. In the Canadian curriculum, there are six basic strands in Elementary Mathematics: Number, Algebra, Data, Spatial Sense, Finan ...

and some work on the arithmetical properties of

infinite series In mathematics, a series is, roughly speaking, a description of the operation of adding infinitely many quantities, one after the other, to a given starting quantity. The study of series is a major part of calculus and its generalization, math ...

. Lubomir Chakalov was a member of the Royal Czech Academy of Sciences, Warsaw Academy of Sciences, and a permanent member of the

Bulgarian Academy of Sciences The Bulgarian Academy of Sciences (abbreviated BAS; bg, Българска академия на науките, ''Balgarska akademiya na naukite'', abbreviated ''БАН'') is the National Academy of Bulgaria, established in 1869. The Academy ...

since 1930. In 1950 he received the Dimitrov Prize and in 1963 he was awarded the title "People's figure of culture." He was an Invited Speaker of the ICM in 1932 in Zurich and in 1936 in Oslo. The National Gymnasium of Natural Sciences and Mathematics "Academician Lyubomir Chakalov" is named after him.

References

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Liubomir Nikolov Chakalov
20th-century Bulgarian mathematicians Members of the Bulgarian Academy of Sciences People from Samokov Rectors of Sofia University 1886 births 1963 deaths {{europe-mathematician-stub