{"id":2273,"date":"2022-03-22T05:54:00","date_gmt":"2022-03-22T04:54:00","guid":{"rendered":"http:\/\/perso.ens-lyon.fr\/ghys\/?p=2273"},"modified":"2022-08-18T06:42:12","modified_gmt":"2022-08-18T05:42:12","slug":"essai","status":"publish","type":"post","link":"https:\/\/perso.ens-lyon.fr\/ghys\/2022\/03\/22\/essai\/","title":{"rendered":"Le prix Abel r\u00e9compense Dennis Sullivan, math\u00e9maticien charismatique"},"content":{"rendered":"\n<p><a href=\"https:\/\/www.lemonde.fr\/sciences\/article\/2022\/03\/23\/le-prix-abel-recompense-dennis-sullivan-mathematicien-charismatique_6118837_1650684.html\">https:\/\/www.lemonde.fr\/sciences\/article\/2022\/03\/23\/le-prix-abel-recompense-dennis-sullivan-mathematicien-charismatique_6118837_1650684.html<\/a><\/p>\n\n\n\n<p><strong>L<\/strong>e prix Abel de math\u00e9matiques <a href=\"https:\/\/www.lemonde.fr\/sciences\/article\/2022\/03\/23\/dennis-parnell-sullivan-mathematicien-americain-recoit-le-prix-abel_6118828_1650684.html\">a \u00e9t\u00e9 attribu\u00e9, mercredi 23&nbsp;mars, \u00e0 l\u2019Am\u00e9ricain Dennis Sullivan<\/a>, 81&nbsp;ans, <em>\u00ab&nbsp;pour ses contributions r\u00e9volutionnaires \u00e0 la topologie dans son sens<\/em> <em>le plus large, et en particulier dans ses aspects alg\u00e9briques, g\u00e9om\u00e9triques et<\/em> <em>dynamiques&nbsp;\u00bb<\/em>, a annonc\u00e9 l\u2019Acad\u00e9mie norv\u00e9gienne des sciences et des lettres. Alors que la m\u00e9daille Fields est attribu\u00e9e \u00e0 un math\u00e9maticien de moins de 40&nbsp;ans, le prix Abel est plus proche du prix Nobel (inexistant en math\u00e9matiques) et r\u00e9compense l\u2019ensemble d\u2019une carri\u00e8re.<\/p>\n\n\n\n<p>Vers la fin du XVII<sup>e<\/sup>&nbsp;si\u00e8cle, Leibniz r\u00eavait de manipuler des formes<em>,<\/em> \u00e0 la mani\u00e8re des symboles abstraits de l\u2019alg\u00e8bre. Il donna le nom d\u2019<em>analysis situs<\/em> \u00e0 cette th\u00e9orie, qu\u2019il ne pourra pas d\u00e9velopper et qui ne sera solidement mise en place qu\u2019\u00e0 la fin du XIX<sup>e<\/sup>&nbsp;si\u00e8cle, par Henri Poincar\u00e9. Dans cette th\u00e9orie, qu\u2019on appelle aujourd\u2019hui topologie, on consid\u00e8re que la surface d\u2019une sph\u00e8re est \u00e9quivalente \u00e0 celle d\u2019un cube, car on peut d\u00e9former l\u2019une en l\u2019autre, si on les imagine fabriqu\u00e9s en caoutchouc. En revanche, la sph\u00e8re n\u2019est pas \u00e9quivalente \u00e0 une chambre \u00e0 air. On \u00e9tudie des courbes, des surfaces et plus g\u00e9n\u00e9ralement des \u00ab&nbsp;vari\u00e9t\u00e9s&nbsp;\u00bb bien plus compliqu\u00e9es, dans des dimensions quelconques. Parmi les contributions majeures de Sullivan, on peut citer sa th\u00e9orie de l\u2019homotopie rationnelle, qui permet de comprendre la structure topologique des vari\u00e9t\u00e9s en leur associant des objets de nature alg\u00e9brique, qu\u2019on peut en principe calculer, r\u00e9alisant en quelque sorte le r\u00eave de Leibniz.<\/p>\n\n\n\n<p><strong>Passerelles insoup\u00e7onn\u00e9es<\/strong><\/p>\n\n\n\n<p>Sullivan passe sans effort d\u2019un chapitre des math\u00e9matiques \u00e0 l\u2019autre et d\u00e9couvre des passerelles insoup\u00e7onn\u00e9es qui le conduisent \u00e0 des points de vue enti\u00e8rement nouveaux. Il \u00e9tablit par exemple un \u00ab&nbsp;dictionnaire&nbsp;\u00bb entre deux th\u00e9ories qu\u2019on croyait ind\u00e9pendantes (les groupes kleiniens et la dynamique holomorphe). Il lui suffit alors de traduire un th\u00e9or\u00e8me de l\u2019une pour obtenir la solution d\u2019un probl\u00e8me important dans l\u2019autre, qui r\u00e9sistait pourtant depuis pr\u00e8s de soixante-dix ans (le th\u00e9or\u00e8me du domaine non errant). Il n\u2019est ni g\u00e9om\u00e8tre, ni topologue, ni alg\u00e9briste, ni analyste&nbsp;: il est un peu tout cela \u00e0 la fois. Tr\u00e8s peu de math\u00e9maticiens ont un sens aussi aigu de la profonde unit\u00e9 des math\u00e9matiques. Depuis quelques ann\u00e9es, il essaye d\u2019exporter ses id\u00e9es topologiques dans un probl\u00e8me majeur de dynamique des fluides. Les experts ne sont pas (encore) convaincus, mais cela conduira peut-\u00eatre \u00e0 un succ\u00e8s retentissant.<\/p>\n\n\n\n<p>C\u2019est aussi par son charisme exceptionnel que Sullivan est remarquable. Il a \u00e9t\u00e9 pendant de nombreuses ann\u00e9es une plaque tournante dans la communaut\u00e9 math\u00e9matique. Toujours entour\u00e9 de chercheurs tr\u00e8s divers, en particulier tr\u00e8s jeunes, il a une incroyable capacit\u00e9 d\u2019\u00e9coute, de partage, de motivation et d\u2019encouragement. Il est \u00e0 l\u2019oppos\u00e9 de l\u2019image d\u2019Epinal du math\u00e9maticien solitaire. Lorsqu\u2019il \u00e9tait professeur \u00e0 l\u2019IHES, \u00e0 Bures-sur-Yvette (Essonne), il fallait le voir \u00e0 l\u2019heure du th\u00e9 mettre en contact des math\u00e9maticiens de tous bords et de tous \u00e2ges qui ne se connaissaient pas, en toute simplicit\u00e9. Son s\u00e9minaire \u00e0 New York est tr\u00e8s fr\u00e9quent\u00e9&nbsp;et n\u2019a rien \u00e0 voir avec un expos\u00e9 traditionnel&nbsp;: les questions fusent de toutes parts et le conf\u00e9rencier doit \u00eatre pr\u00e9par\u00e9 \u00e0 parler pendant de nombreuses heures, jusqu\u2019\u00e0 l\u2019\u00e9puisement g\u00e9n\u00e9ral. Il est l\u2019un des premiers \u00e0 avoir enregistr\u00e9 ces s\u00e9minaires sur des cassettes vid\u00e9o VHS, d\u00e8s le d\u00e9but des ann\u00e9es 1980. Ce sont aujourd\u2019hui des collectors.<\/p>\n\n\n\n<p>Un jour, j\u2019\u00e9tais assis \u00e0 c\u00f4t\u00e9 de lui pendant une conf\u00e9rence o\u00f9 je ne comprenais pas un tra\u00eetre mot de ce que disait le conf\u00e9rencier. Alors que je lui demandais si c\u2019\u00e9tait son cas, il me r\u00e9pondit&nbsp;: <em>\u00ab&nbsp;Je ne comprends pas les paroles, mais j\u2019\u00e9coute la musique math\u00e9matique&nbsp;!&nbsp;\u00bb<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>https:\/\/www.lemonde.fr\/sciences\/article\/2022\/03\/23\/le-prix-abel-recompense-dennis-sullivan-mathematicien-charismatique_6118837_1650684.html Le prix Abel de math\u00e9matiques a \u00e9t\u00e9 attribu\u00e9, mercredi 23&nbsp;mars, \u00e0 l\u2019Am\u00e9ricain Dennis Sullivan, 81&nbsp;ans, \u00ab&nbsp;pour ses contributions r\u00e9volutionnaires \u00e0 la topologie dans son sens le plus large, et en particulier dans ses aspects alg\u00e9briques, g\u00e9om\u00e9triques et dynamiques&nbsp;\u00bb, a annonc\u00e9 l\u2019Acad\u00e9mie norv\u00e9gienne des sciences et des lettres. Alors que la m\u00e9daille Fields est attribu\u00e9e &hellip; <a href=\"https:\/\/perso.ens-lyon.fr\/ghys\/2022\/03\/22\/essai\/\" class=\"more-link\">Continuer la lecture de <span class=\"screen-reader-text\">Le prix Abel r\u00e9compense Dennis Sullivan, math\u00e9maticien charismatique<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","ub_ctt_via":"","_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"episode_type":"","audio_file":"","cover_image":"","cover_image_id":"","duration":"","filesize":"","date_recorded":"","explicit":"","block":"","itunes_episode_number":"","itunes_title":"","itunes_season_number":"","itunes_episode_type":"","filesize_raw":"","footnotes":""},"categories":[57],"tags":[],"class_list":["post-2273","post","type-post","status-publish","format-standard","hentry","category-le-monde"],"featured_image_src":null,"author_info":{"display_name":"ghys","author_link":"https:\/\/perso.ens-lyon.fr\/ghys\/author\/ghys\/"},"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.4 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Le prix Abel r\u00e9compense Dennis Sullivan, math\u00e9maticien charismatique - \u00c9tienne Ghys<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/perso.ens-lyon.fr\/ghys\/2022\/03\/22\/essai\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Le prix Abel r\u00e9compense Dennis Sullivan, math\u00e9maticien charismatique - \u00c9tienne Ghys\" \/>\n<meta property=\"og:description\" content=\"https:\/\/www.lemonde.fr\/sciences\/article\/2022\/03\/23\/le-prix-abel-recompense-dennis-sullivan-mathematicien-charismatique_6118837_1650684.html Le prix Abel de math\u00e9matiques a \u00e9t\u00e9 attribu\u00e9, mercredi 23&nbsp;mars, \u00e0 l\u2019Am\u00e9ricain Dennis Sullivan, 81&nbsp;ans, \u00ab&nbsp;pour ses contributions r\u00e9volutionnaires \u00e0 la topologie dans son sens le plus large, et en particulier dans ses aspects alg\u00e9briques, g\u00e9om\u00e9triques et dynamiques&nbsp;\u00bb, a annonc\u00e9 l\u2019Acad\u00e9mie norv\u00e9gienne des sciences et des lettres. 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Alors que la m\u00e9daille Fields est attribu\u00e9e &hellip; Continuer la lecture de Le prix Abel r\u00e9compense Dennis Sullivan, math\u00e9maticien charismatique &rarr;","og_url":"https:\/\/perso.ens-lyon.fr\/ghys\/2022\/03\/22\/essai\/","og_site_name":"\u00c9tienne Ghys","article_published_time":"2022-03-22T04:54:00+00:00","article_modified_time":"2022-08-18T05:42:12+00:00","author":"ghys","twitter_card":"summary_large_image","twitter_misc":{"\u00c9crit par":"ghys","Dur\u00e9e de lecture estim\u00e9e":"4 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/perso.ens-lyon.fr\/ghys\/2022\/03\/22\/essai\/","url":"https:\/\/perso.ens-lyon.fr\/ghys\/2022\/03\/22\/essai\/","name":"Le prix Abel r\u00e9compense Dennis Sullivan, math\u00e9maticien charismatique - \u00c9tienne Ghys","isPartOf":{"@id":"https:\/\/perso.ens-lyon.fr\/ghys\/#website"},"datePublished":"2022-03-22T04:54:00+00:00","dateModified":"2022-08-18T05:42:12+00:00","author":{"@id":"https:\/\/perso.ens-lyon.fr\/ghys\/#\/schema\/person\/069f6bb9d42c992d92bef80c575edce9"},"breadcrumb":{"@id":"https:\/\/perso.ens-lyon.fr\/ghys\/2022\/03\/22\/essai\/#breadcrumb"},"inLanguage":"fr-FR","potentialAction":[{"@type":"ReadAction","target":["https:\/\/perso.ens-lyon.fr\/ghys\/2022\/03\/22\/essai\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/perso.ens-lyon.fr\/ghys\/2022\/03\/22\/essai\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Accueil","item":"https:\/\/perso.ens-lyon.fr\/ghys\/accueil\/"},{"@type":"ListItem","position":2,"name":"Le prix Abel r\u00e9compense Dennis Sullivan, math\u00e9maticien charismatique"}]},{"@type":"WebSite","@id":"https:\/\/perso.ens-lyon.fr\/ghys\/#website","url":"https:\/\/perso.ens-lyon.fr\/ghys\/","name":"\u00c9tienne Ghys","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/perso.ens-lyon.fr\/ghys\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"fr-FR"},{"@type":"Person","@id":"https:\/\/perso.ens-lyon.fr\/ghys\/#\/schema\/person\/069f6bb9d42c992d92bef80c575edce9","name":"ghys","image":{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/perso.ens-lyon.fr\/ghys\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/4482fb1bb546b94acf8ae35749ecbb87a8515a7bdaf0a461022cdc80db4db941?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/4482fb1bb546b94acf8ae35749ecbb87a8515a7bdaf0a461022cdc80db4db941?s=96&d=mm&r=g","caption":"ghys"},"url":"https:\/\/perso.ens-lyon.fr\/ghys\/author\/ghys\/"}]}},"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"post-thumbnail":false},"uagb_author_info":{"display_name":"ghys","author_link":"https:\/\/perso.ens-lyon.fr\/ghys\/author\/ghys\/"},"uagb_comment_info":0,"uagb_excerpt":"https:\/\/www.lemonde.fr\/sciences\/article\/2022\/03\/23\/le-prix-abel-recompense-dennis-sullivan-mathematicien-charismatique_6118837_1650684.html Le prix Abel de math\u00e9matiques a \u00e9t\u00e9 attribu\u00e9, mercredi 23&nbsp;mars, \u00e0 l\u2019Am\u00e9ricain Dennis Sullivan, 81&nbsp;ans, \u00ab&nbsp;pour ses contributions r\u00e9volutionnaires \u00e0 la topologie dans son sens le plus large, et en particulier dans ses aspects alg\u00e9briques, g\u00e9om\u00e9triques et dynamiques&nbsp;\u00bb, a annonc\u00e9 l\u2019Acad\u00e9mie norv\u00e9gienne des sciences et des lettres. Alors que la m\u00e9daille Fields est attribu\u00e9e\u2026","_links":{"self":[{"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/posts\/2273","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/comments?post=2273"}],"version-history":[{"count":2,"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/posts\/2273\/revisions"}],"predecessor-version":[{"id":2278,"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/posts\/2273\/revisions\/2278"}],"wp:attachment":[{"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/media?parent=2273"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/categories?post=2273"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/perso.ens-lyon.fr\/ghys\/wp-json\/wp\/v2\/tags?post=2273"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}