Frans Oort

{{short description|Dutch mathematician}} {{Infobox scientist | name = Frans Oort | image = Frans Oort.jpg  | image_size = | image_upright = | alt = | caption = Oort at Oberwolfach, 2004 | birth_date = {{birth date and age |1935|7|17|df=y}} | birth_place = Bussum, Netherlands | death_date =  | death_place = | fields = Mathematics | workplaces = | alma_mater = University of Leiden | thesis_title =  | thesis_url =  | thesis_year =  | doctoral_advisors = {{ill|Willem Titus van Est|de}} Jaap Murre | doctoral_students = Bas Edixhoven Michiel Hazewinkel Aise Johan de Jong Hendrik Lenstra Joseph Steenbrink | known_for = André–Oort conjecture | awards = }}

'''Frans Oort''' (born 17 July 1935) is a Dutch mathematician who specializes in algebraic geometry.

==Career== Oort studied from 1952 to 1958 at Leiden University, where he graduated with a thesis on elliptic curves. He received his doctorate in 1961 in Leiden from {{ill|Willem Titus van Est|de}} and Jaap Murre with thesis ''Reducible and Multiple Algebraic Curves'',<ref name=MathGen>{{MathGenealogy|id=26911}}</ref> but had previously studied under Jean-Pierre Serre in Paris and Aldo Andreotti in Pisa. Oort was from 1961 at the University of Amsterdam, where he became a professor in 1967. In 1977, until his retirement in 2000, he was a professor at Utrecht University.<ref name=AE>{{cite web|title=Frans Oort|publisher=Academia Europaea|url=http://www.ae-info.org/ae/Member/Oort_Frans}}</ref>

He was a visiting scholar at several academic institutions, including Harvard University (1966/67) and Aarhus University (1972/73). In 2008 he was the Eilenberg Professor at Columbia University.<ref>{{cite web|url=https://www.ae-info.org/ae/Member/Oort_Frans/CV|title=Curriculum vitae: Frans Oort|publisher=Academia Europaea|access-date=2025-04-02}}</ref>

His doctoral students include Bas Edixhoven, Michiel Hazewinkel, Aise Johan de Jong, Hendrik Lenstra and Joseph Steenbrink.<ref name=MathGen/>

==Research== Oort's research deals with, among other topics, abelian varieties and their moduli. In 1994, he formulated what is now known as the André–Oort conjecture (generalizing a conjecture made in 1989 by Yves André).<ref>{{cite book|author=Zannier, Umberto|author-link=Umberto Zannier|title=Some problems of unlikely intersections in arithmetic and geometry|year=2012|publisher=Princeton University Press|page=9|url=https://books.google.com/books?id=S-bYWbSDHLIC&pg=PA9|isbn=978-0-691-15371-1}}</ref> In 2000 Oort proved a conjecture made by Grothendieck in 1970.<ref>{{Cite journal|author=Oort, Frans|title=Newton polygons and formal groups: Conjectures by Manin and Grothendieck|journal=Ann. of Math. |series=Series 2 |volume=152 |issue=1|pages=183–206|year=2000|arxiv=math/0007201 |doi=10.2307/2661381|jstor=2661381|bibcode=2000math......7201O|s2cid=18575416}}</ref>

==Awards and honors== In 1962, Oort made a short contribution ''Multiple algebraic curves'' at the International Congress of Mathematicians in Stockholm, but was not an invited speaker. In 2011 he was elected a member of Academia Europaea.<ref name=AE/> In July 2013, he gave a talk at the International Congress of Chinese Mathematicians in Taipei.<ref>{{cite journal|author=Oort, Frans|title=Prime numbers|journal=Notices of the International Congress of Chinese Mathematicians|volume= 1|issue=2|pages=60–78|date=November 2013|url=https://www.intlpress.com/site/pub/files/_fulltext/journals/iccm/2013/0001/0002/ICCM-2013-0001-0002-a008.pdf|doi=10.4310/iccm.2013.v1.n2.a8|doi-access=free}}</ref>

==Personal life== Oort married and later divorced author {{ill|Marijke Harberts|nl}} (1936–2020).<ref name="Pers">{{cite web | last=Pers | first=Primavera | title=Marijke Harberts (1934-2020) | website=Primavera Pers | url=https://www.primaverapers.nl/nieuws/marijke-harberts-1934-2020/ | language=nl | access-date=22 November 2022}}</ref>

==Selected publications== * ''Commutative group schemes'', Springer 1966; {{cite book|title=pbk reprint|year=2006|url=https://books.google.com/books?id=czDtCAAAQBAJ|isbn=978-3-540-37171-7|last1=Oort|first1=F|publisher=Springer }} * as editor: ''Algebraic Geometry'', Oslo 1970, Wolters-Noordhoff 1972 * with Ke-Zheng Li: [https://books.google.com/books?id=NAwU_M_6UKAC ''Moduli of supersingular abelian varieties''], Springer 1998 * as editor with Steenbrink and van der Geer: '' Arithmetic algebraic geometry '', Birkhäuser 1991; {{cite book|title=pbk reprint 2012|url=https://books.google.com/books?id=rUHhBwAAQBAJ|isbn=978-1-4612-0457-2|last1=g|first1=van der Geer|last2=Oort|first2=F|last3=Steenbrink|first3=J.H.M|date=2012-12-06| publisher=Springer }} * as editor with Carel Faber and Gerard van der Geer: [https://books.google.com/books?id=DfQW3YHLGIEC ''Moduli of abelian varieties''], Birkhäuser 2001 * {{cite book|chapter=''Did earlier thoughts inspire Grothendieck?'' by Frans Oort|title=''In:'' Alexander Grothendieck: A mathematical portrait|editor=L. Schneps|publisher=International Press|location=Sommerville, Massachusetts|year=2014|pages=231–268|s2cid=17286534}} * with Ching-Li Chai: {{cite journal|title=Life and work of Alexander Grothendieck|journal=ICCM Notices|volume=5|year=2017|pages=22–50|doi=10.4310/iccm.2017.v5.n1.a2|s2cid=34440499|last1=Chai|first1=Ching-Li|last2=Oort|first2=Frans}}

==References== <references/>

==External links== * [http://www.math.uu.nl/people/oort/ Homepage in Utrecht] * {{cite web|title=Frans Oort on "John Tate receives the 2010 Abel Prize"|date=23 January 2016|website=YouTube|url=https://www.youtube.com/watch?v=MVQnmfZsZv4}}

{{DEFAULTSORT:Oort, Frans}} Category:20th-century Dutch mathematicians Category:21st-century Dutch mathematicians Category:Algebraic geometers Category:Leiden University alumni Category:Academic staff of the University of Amsterdam Category:Academic staff of Utrecht University Category:Members of Academia Europaea Category:1935 births Category:Living people