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	~~Airconditioning~~ and ~~Mechanical Services Plumber Rocky from Labrador City~~, ~~has hobbies~~ such as ~~saltwater aquariums~~, ~~como~~ [http://~~comoficarrico~~.~~comoganhardinheiro101~~.com/ ~~ganhar dinheiro~~] ~~na internet and rc model cars~~. ~~Likes to go to unknown places for example Summer Palace~~.		{{Distinguish\|Israel Gelfand}}
			{{Infobox scientist
			\|name = Alexander Gelfond
			\|image =
			\|image_size =250px
			\|caption = Alexander Gelfond
			\|birth_date = 24 October 1906
			\|birth_place = [[Saint Petersburg]], [[Russian Empire]]
			\|death_date = 7 November 1968
			\|death_place = [[Moscow]], [[Soviet Union]]
			\|residence =
			\|citizenship = [[Soviet Union]]
			\|nationality = [[Soviet Union]]
			\|ethnicity =
			\|field = [[Mathematics]]
			\|work_institutions = [[Moscow State University]] <br /> [[Steklov Mathematical Institute]]
			\|alma_mater = [[Moscow State University]]
			\|doctoral_advisor = [[Aleksandr Yakovlevich Khinchin\|Alexander Khinchin]] <br /> [[Vyacheslav Stepanov]]
			\|doctoral_students = [[Gregory Freiman]]
			\|known_for = [[Gelfond's theorem]]
			\|author_abbrev_bot =
			\|author_abbrev_zoo =
			\|influences =
			\|influenced =
			\|prizes =
			\|religion =
			\|footnotes =
			\|signature =
			}}
			'''Alexander Osipovich Gelfond''' ({{lang-ru\|Алекса́ндр О́сипович Ге́льфонд}}; 24 October 1906 – 7 November 1968) was a [[Soviet Union\|Soviet]] mathematician. [[Gelfond's theorem]] is named after him.

			==Biography==

			Alexander Gelfond was born in Saint Petersburg, [[Russian Empire]] in the family of a professional [[physician]] and amateur [[philosopher]] Osip Isaakovich Gelfond. He entered the [[Moscow State University]] in 1924, started his postgraduate studies there in 1927 and obtained his [[Doctor of Philosophy\|PhD]] in 1930. His advisors were [[Aleksandr Yakovlevich Khinchin\|Alexander Khinchin]] and [[Vyacheslav Stepanov]].

			In 1930 he stayed for five months in [[Germany]] (in [[Berlin]] and [[Göttingen]]) where he worked with [[Edmund Landau]], [[Carl Ludwig Siegel]] and [[David Hilbert]]. In 1931 he started teaching as a Professor at the Moscow State University and worked there until the last day of his life. Since 1933 he also worked at the [[Steklov Institute of Mathematics]].

			In 1939 he was elected a [[Corresponding member]] of the [[Academy of Sciences of the Soviet Union]] for his works in the field of [[Cryptography]]. According to [[Vladimir Arnold]], during [[World War II]] Gelfond was the Chief Cryptographer of the [[Soviet Navy]].<ref>{{cite news\|last=Arnold\|first=Vladimir\|title=Владимир Арнольд: "Опасаться компетентных соперников очень естественно для начальников" \|url=http://young-science.ru/sections/expertise/31-qq/1898-l-0q---.html\|newspaper=[[Gazeta.ru]]\|date=3 June 2006\|authorlink=Vladimir Arnold\|language=Russian\|archiveurl = http://www.webcitation.org/5uGGuMdFk \|archivedate = 2010-11-15\|deadurl=no}}</ref>

			==Results==
			Gelfond obtained important results in several mathematical domains including [[number theory]], [[theory of analytic functions\|analytic functions]], [[integral equation]]s and the [[history of mathematics]], but his most famous result is his [[Gelfond's theorem\|eponymous theorem]]:
			:If α and β are [[algebraic number]]s (with α≠0 and α≠1), and if β is not a [[real number\|real]] [[rational number]], then any value of α<sup>β</sup> is a [[transcendental number]].

			This is the famous [[Hilbert's seventh problem\|7th Hilbert's problem]]. Gelfond proved a special case of the theorem in 1929, when he was a postgraduate student and fully proved it in 1934. The same theorem was independently proved by [[Theodor Schneider]] and so the theorem is often known as the [[Gelfond–Schneider theorem]]. In 1929 Gelfond proposed an extension of the theorem known as the [[Gelfond's conjecture]] that was proved by [[Alan Baker (mathematician)\|Alan Baker]] in 1966.

			Before Gelfond's works only a few numbers such as ''[[E (mathematical constant)\|e]]'' and [[Pi\|π]] were known to be transcendental. After his works an infinite number of transcendentals could be easily obtained. Some of them are named in Gelfond's honor:
			* <math>2^{\sqrt{2}}</math> is known as the [[Gelfond–Schneider constant]]
			* <math>e^\pi \,</math> is known as [[Gelfond's constant]].

			==Notes==
			{{reflist}}

			==References==
			* {{Cite book \| last1=Gel'fond \| first1=A. O. \| title=Transcendental and algebraic numbers \| origyear=1952 \| url=http://books.google.com/books?isbn=0486495264 \| publisher=[[Dover Publications]] \| location=New York \| series=Dover Phoenix editions \| isbn=978-0-486-49526-2 \| mr=0057921 \| year=1960 }}
			* {{cite journal \| author=B.V. Levin, N.I. Feldman, A.B. Sidlovsky \| title= Alexander O. Gelfond \| journal= Acta Arithmetica\| year= 1971\| volume=17 \| issue= \| pages= 315–336\| url= http://matwbn.icm.edu.pl/ksiazki/aa/aa17/aa1741.pdf \|date=January 2010}}
			* {{MacTutor\|id=Gelfond}}

			==External links==
			* {{MathGenealogy \|id=56858}}

			{{Authority control\|VIAF=101651}}
			{{Persondata <!-- Metadata: see [[Wikipedia:Persondata]]. -->
			\| NAME = Gelfond, Alexander Osipovich
			\| ALTERNATIVE NAMES =
			\| SHORT DESCRIPTION = Soviet cryptographer
			\| DATE OF BIRTH = 24 October 1906
			\| PLACE OF BIRTH = [[Saint Petersburg]], [[Russian Empire]]
			\| DATE OF DEATH = 7 November 1968
			\| PLACE OF DEATH = [[Moscow]], [[Soviet Union]]
			}}
			{{DEFAULTSORT:Gelfond, Alexander Osipovich}}
			[[Category:Number theorists]]
			[[Category:1906 births]]
			[[Category:1968 deaths]]
			[[Category:20th-century mathematicians]]
			[[Category:Russian mathematicians]]
			[[Category:Russian Jews]]
			[[Category:Russian cryptographers]]
			[[Category:Soviet mathematicians]]
			[[Category:People from Saint Petersburg]]
			[[Category:Moscow State University alumni]]
			[[Category:Moscow State University faculty]]

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Airconditioning and Mechanical Services Plumber Rocky from Labrador City, has hobbies such as saltwater aquariums, como [http://comoficarrico.comoganhardinheiro101.com/ ganhar dinheiro] na internet and rc model cars. Likes to go to unknown places for example Summer Palace.

Uniform algebra - Revision history

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