{{Short description|French mathematician}} {{distinguish|text=his wife and colleague, [[Michèle Raynaud]]}} {{Infobox scientist | name = Michel Raynaud | image = | image_size = | caption = | birth_date = {{birth date|1938|6|16|df=y}} | birth_place = [[Riom]], France | death_date = {{death date and age|2018|3|10|1938|6|16|df=y}} | death_place = [[Rueil-Malmaison]], France | fields = [[Mathematics]] | workplaces = Paris-Sud 11 University | alma_mater = [[Paris-Sud 11 University]] | doctoral_advisor = [[Alexander Grothendieck]] | doctoral_students = | known_for = [[Abhyankar's conjecture]]{{br}}[[Manin–Mumford conjecture]]{{br}}[[Raynaud surface]]{{br}}[[Raynaud's isogeny theorem]] | awards = [[Cole Prize]] (1995)<br>[[Prize Ampère]] (1987) }} '''Michel Raynaud''' ({{IPA|fr|ʁɛno|lang}}; 16 June 1938 – 10 March 2018<ref name="SMF">[http://smf.emath.fr/content/d%C3%A9c%C3%A8s-de-michel-raynaud Décès de Michel Raynaud]. Société Mathématique de France.</ref>) was a French [[mathematician]] working in [[algebraic geometry]]<ref name="smf-obit">{{Cite web |url=https://smf.emath.fr/actualites-smf/deces-de-michel-raynaud |title=Décès de Michel Raynaud |last=Gassiat |first=Elisabeth|author-link=Élisabeth Gassiat |date=March 2018 |website=Société Mathématique de France |language=fr |access-date=2018-03-14}}</ref> and a professor at [[Paris-Sud 11 University]].
== Early life and education == He was born in [[Riom]], France as a single son to a modest household. His father was a carpenter and his mother cleaned houses.<ref name=":0">{{Cite journal|last=Illusie|first=Luc|author-link=Luc Illusie|title=Michel Raynaud (1938–2018)|url=https://www.ams.org/journals/notices/201901/rnoti-p37.pdf |year=2019|archive-url=|archive-date=|access-date=18 August 2020|journal=[[Notices of the American Mathematical Society]]|volume=66|issue=1|doi=10.1090/noti1764 |s2cid=125558400 }}</ref> He attended the local primary school at [[Châtel-Guyon|Châtel Guyon]] and Riom, and attended high school at the boarding school in [[Clermont-Ferrand]].<ref name=":0" />
Raynaud entered the [[École normale supérieure (Paris)|École normale supérieure]] where he studied from 1958 to 1962, while being first of the class in the "agrégation" exam where the new high school teachers were selected in 1961.<ref name=":0" /> In 1962, he entered the [[French National Centre for Scientific Research]] where he studied together with his future wife [[Michèle Chaumartin]]. Both had the same doctoral advisor in [[Alexander Grothendieck]]. Raynaud received his doctoral degree in 1967.<ref name=":0" />
==Career== Raynaud was hired as professor at the [[Orsay Faculty of Sciences]] in Paris where he was employed until 2001, when he retired.<ref name=":0" />
Raynaud died on 10 March 2018 in [[Rueil-Malmaison]], France.<ref name="SMF"/>
==Research== In 1983, Raynaud published a proof of the [[Manin–Mumford conjecture]].<ref>{{cite book | first=Michel | last=Raynaud | authorlink=Michel Raynaud | chapter=Sous-variétés d'une variété abélienne et points de torsion | language=French | editor1-last=Artin | editor1-first=Michael | editor1-link=Michael Artin | editor2-last=Tate | editor2-first=John | editor2-link=John Tate (mathematician) | title=Arithmetic and geometry. Papers dedicated to I. R. Shafarevich on the occasion of his sixtieth birthday. Vol. I: Arithmetic | series=Progress in Mathematics | volume=35 | publisher=[[Birkhäuser|Birkhäuser Boston]]|location=Boston, MA | year=1983 | pages= 327–352 |mr=0717600| zbl=0581.14031 }}</ref> In 1985, he proved [[Raynaud's isogeny theorem]] on [[Faltings height]]s of isogenous [[elliptic curves]].<ref>{{cite book | last1=Raynaud | first1=Michel | author1-link=Michel Raynaud | editor1-last=Szpiro | editor1-first=Lucien | title=Séminaire sur les pinceaux arithmétiques: la conjecture de Mordell | trans-title=Seminar on arithmetic pencils: the Mordell conjecture | language=French | publisher=Société Mathématique de France | location=Paris | zbl=1182.14049 | mr=801923 | year=1985 | series=[[Astérisque]] | issn=0303-1179 | issue=127 | chapter=Hauteurs et isogénies | trans-chapter=Heights and isogenies | pages=199–234 }}</ref> With [[David Harbater]] and following the work of [[Jean-Pierre Serre]], Raynaud proved [[Abhyankar's conjecture]] in 1994.<ref>{{cite journal |first=Michel |last=Raynaud |title=Revêtements de la droite affine en caractéristique p > 0 |journal=Inventiones Mathematicae |volume=116 |issue=1 |year=1994 |pages=425–462 | doi=10.1007/BF01231568 | zbl=0798.14013 |bibcode=1994InMat.116..425R |s2cid=122286118 }}.</ref><ref>{{cite journal |first=David |last=Harbater |year=1994 |title=Abhyankar's conjecture on Galois groups over curves |journal=Inventiones Mathematicae |volume=117 |issue=1 |pages=1–25 | doi=10.1007/BF01232232 | zbl=0805.14014 |bibcode=1994InMat.117....1H |s2cid=121690794 }}.</ref><ref name=FJ70>{{cite book | last1=Fried | first1=Michael D. | last2=Jarden | first2=Moshe |author-link=Michael D. Fried |author-link2=Moshe Jarden | title=Field arithmetic | edition=3rd | series=Ergebnisse der Mathematik und ihrer Grenzgebiete. 3. Folge | volume=11 | publisher=[[Springer-Verlag]] | year=2008 | isbn=978-3-540-77269-9 | zbl=1145.12001 | page=70 }}</ref>
The [[Raynaud surface]] was named after him by William E. Lang in 1979.<ref>{{cite journal | last1=Lang | first1=William E. | title=Quasi-elliptic surfaces in characteristic three | url=http://www.numdam.org/item?id=ASENS_1979_4_12_4_473_0 |mr=565468 | year=1979 | journal=[[Annales Scientifiques de l'École Normale Supérieure]] |series=Série 4 | issn=0012-9593 | volume=12 | issue=4 | pages=473–500| doi=10.24033/asens.1373 | doi-access=free }}</ref><ref>{{cite book | last1=Lang | first1=William E. | title=Arithmetic and geometry, Vol. II | publisher=Birkhäuser Boston | location=Boston, MA | series=Progress in Mathematics |mr=717611 | year=1983 | volume=36 | chapter=Examples of surfaces of general type with vector fields | pages=167–173}}</ref>
== Honors and awards == In 1970 Raynaud was an [[List of International Congresses of Mathematicians Plenary and Invited Speakers|invited speaker]] at the [[International Congress of Mathematicians]] in [[Nice]]. In 1987 he received the [[Prize Ampère]] from the [[French Academy of Sciences]]. In 1995 he received the [[Cole Prize]], together with [[David Harbater]], for his solution of the [[Abhyankar conjecture]].<ref name=":0" />
== Personal life == He practiced skiing (especially in [[Val-d'Isère]]), tennis, and rock climbing (in [[Fontainebleau]]).<ref name="smf-obit" /> He was married to the mathematician [[Michèle Raynaud]] ({{nee|Chaumartin}})<ref name=":0" /> who also worked with [[Alexander Grothendieck]].
==References== {{reflist}}
== External links == * {{MathGenealogy|id=77935}} * [https://www.ams.org/notices/199504/prize-cole.pdf Cole Prize citation for Michel Raynaud] * {{cite journal | last = Illusie | first =Luc |author-link=Luc Illusie |date=January 2019 | title = Michel Raynaud (1938–2018) | journal = [[Notices of the American Mathematical Society]] | volume = 66 | issue = 1 | pages = 37–41 | doi =10.1090/noti1764 | url = https://www.ams.org/publications/journals/notices/201901/rnoti-p37.pdf| doi-access = free }} {{Authority control}}
{{DEFAULTSORT:Raynaud, Michel}} [[Category:1938 births]] [[Category:2018 deaths]] [[Category:People from Riom]] [[Category:20th-century French mathematicians]] [[Category:21st-century French mathematicians]] [[Category:École normale supérieure (Paris) alumni]] [[Category:Academic staff of Paris-Sud University]] [[Category:Institute for Advanced Study visiting scholars]] [[Category:Members of the French Academy of Sciences]] [[Category:Algebraic geometers]]