Pafnuty Chebyshev
Categories: 1821 births | 1894 deaths | Russian mathematicians | Number theorists | Statisticians
Pafnuty Lvovich Chebyshev (Пафну́тий Льво́вич Чебышёв) (May 16 1821 - December 9 1894) was a Russian mathematician. His name is also transliterated as Chebyshov, Tchebycheff or Tschebyscheff (obsolete French and German transcriptions).
He was born in central Russian village Okatovo near Borovsk, in the family of Agrafena Ivanova Pozniakova and Lev Pavlovich Chebyshev with 9 children. His father fought as an officer against Napoleon's invading army.
He was originally home-schooled by his mother and his cousin Avdotia Kvintillianova Soukhareva. He learned French early in life that helped him in the future to communicate with other mathematicians. From childhood he had one leg longer than another that prevented him from playing with other kids, leading him to concentrate on studying instead.
Later he studied at Moscow University obtaining his degree in 1841.
He was a student of Nikolai Brashman. His own most illustrious student was Andrei Markov, although also well-known for the method that bears his name is Alexandr Liapunov.
He is known for his work in the field of probability and statistics. Chebyshev's inequality says that the probability that the outcome of a random variable is no less than a standard deviations away from its mean is no more than 1/a2:
- <math>P(|X - {\mathbf E}(X)| \ge a\,\operatorname{sdev}(X)) \le \frac {1}{a^2} </math>
Chebyshev's inequality is used to prove the weak law of large numbers and the Bertrand-Chebyshev theorem (1845|1850) that the number of prime numbers less than <math>n</math> is <math>p(n)=n/\log(n)+o(n)</math>.
See also
- Bienaymé-Chebyshev inequality - (1853|1866)
- Chebyshev distance
- Chebyshev filter, in electronics and signal processing, a family of electronic filters
- Chebyshev polynomials
- Chebyshev's sum inequality
External link
es:Pafnuty Chebyshev eo:Pafnuti ĈEBIŜEV fr:Pafnouti Tchebychev it:Pafnuti Cebicev he:פפנוטי צ'בישב hu:Csebisev nl:Pafnoeti Lvovitsj Tsjebysjev no:Pafnutij Tsjebysjev pl:Pafnutij L. Czebyszew pt:Pafnuti Tchebychev ru:Чебышёв, Пафнутий Львович sl:Pafnuti Lvovič Čebišov