Ljubomir Chakaloff (or Lubomir Nikolov Chakalov, ) was a

Bulgaria Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...

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, mathematical structure, structure, space, Mathematica ...

. He was born in 1886 in

Samokov Samokov ( ) List of cities and towns in Bulgaria, is a town in Sofia Province in the southwest of Bulgaria. It is situated in Samokov Valley between the mountain ranges of Rila, Vitosha and Sredna Gora, 55 kilometres from the capital Sofia. Due ...

and died in 1963 at the age of 77.

Education

He graduated from

Sofia University Sofia University "St. Kliment Ohridski" () is a public university, public research university in Sofia, Bulgaria. It is the oldest institution of higher education in Bulgaria. Founded on 1 October 1888, the edifice of the university was constr ...

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 (; , ) is a public university, public research university in Naples, Campania, Italy. Established in 1224 and named after its founder, Frederick II, Holy Roman Emperor, Frederick II, it is the oldest public, s ...

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( ...

s, having as advisor Ernesto Pascal.

Recognitions

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

number theory Number theory is a branch of pure mathematics devoted primarily to the study of the integers and arithmetic functions. Number theorists study prime numbers as well as the properties of mathematical objects constructed from integers (for example ...

, differential equations,

elementary mathematics Elementary mathematics, also known as primary or secondary school mathematics, is the study of mathematics topics that are commonly taught at the primary or secondary school levels around the world. It includes a wide range of mathematical c ...

and some work on the arithmetical properties of

infinite series In mathematics, a series is, roughly speaking, an addition of infinitely many terms, one after the other. The study of series is a major part of calculus and its generalization, mathematical analysis. Series are used in most areas of mathemati ...

. 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; , ''Bŭlgarska akademiya na naukite'', abbreviated БАН) is the National Academy of Bulgaria, established in 1869. The Academy, with headquarters in Sofia, is autonomous and consists of a S ...

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 ICM may refer to: Organizations * Irish Church Missions, an Anglican mission * Institut du Cerveau, the Paris Brain Institute, a research center * Interdisciplinary Centre for Mathematical and Computational Modelling, University of Warsaw * Interna ...

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

*
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