Aleksey Vasilyevich Letnikov (russian: Алексéй Васи́льевич Лéтников, link=no, 1837–1888) was a Russian mathematician. After graduating from the Konstantinovsky Land-Surveying Institute (russian: Константиновский Межевой Институт) in

Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 million ...

, Letnikov attended classes at

Moscow University M. V. Lomonosov Moscow State University (MSU; russian: Московский государственный университет имени М. В. Ломоносова) is a public research university in Moscow, Russia and the most prestigious ...

and the

Sorbonne Sorbonne may refer to: * Sorbonne (building), historic building in Paris, which housed the University of Paris and is now shared among multiple universities. *the University of Paris (c. 1150 – 1970) *one of its components or linked institution, ...

. In 1860 he became an Instructor of Mathematics at the Konstantinovsky Institute. He obtained the degrees of

Master Master or masters may refer to: Ranks or titles * Ascended master, a term used in the Theosophical religious tradition to refer to spiritually enlightened beings who in past incarnations were ordinary humans *Grandmaster (chess), National Master ...

and

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is a ...

from Moscow University in 1868 and 1874 respectively. In 1868 Letnikov became a professor at the

Imperial Moscow Technical School The Bauman Moscow State Technical University, BMSTU (russian: link=no, Московский государственный технический университет им. Н. Э. Баумана (МГТУ им. Н. Э. Баумана)), some ...

and from 1879 to 1880 was an Inspector at the school. From 1883 he was the principal of the Aleksandrov Commercial School (russian: Александровское коммерческое училище, currently

The State University of Management The State University of Management is a public university in Moscow, Russia. It was founded in 1919. Its rector is Ivan Vasilyevich Lobanov. There are more than 250 professors and 12 academics and members of the Russian Academy of Sciences workin ...

br>
and from 1884 he was a Corresponding Member of the

Russian Academy of Sciences The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across t ...

. His most renowned contribution to mathematics was the creation of the

Grünwald–Letnikov derivative In mathematics, the Grünwald–Letnikov derivative is a basic extension of the derivative in fractional calculus that allows one to take the derivative a non-integer number of times. It was introduced by Anton Karl Grünwald (1838–1920) from P ...

. He also published results in the fields of analytic geometry,

ordinary differential equation In mathematics, an ordinary differential equation (ODE) is a differential equation whose unknown(s) consists of one (or more) function(s) of one variable and involves the derivatives of those functions. The term ''ordinary'' is used in contras ...

s, and

non-Euclidean geometry In mathematics, non-Euclidean geometry consists of two geometries based on axioms closely related to those that specify Euclidean geometry. As Euclidean geometry lies at the intersection of metric geometry and affine geometry, non-Euclidean ...

. Letnikov died in Moscow in 1888 and was buried in the cemetery of the Novo-Alekseyevsky Monaster

References

"Letnikov"
in the ''

Brockhaus and Efron Encyclopedic Dictionary The ''Brockhaus and Efron Encyclopaedic Dictionary'' ( Russian: Энциклопедический словарь Брокгауза и Ефрона, abbr. ЭСБЕ, tr. ; 35 volumes, small; 86 volumes, large) is a comprehensive multi-volume ...

'' {{DEFAULTSORT:Letnikov, Aleksey Letnikov Letnikov Corresponding members of the Saint Petersburg Academy of Sciences Moscow State University alumni Mathematicians from the Russian Empire Letnikov