{"id":764,"date":"2017-04-03T20:23:22","date_gmt":"2017-04-03T17:23:22","guid":{"rendered":"https:\/\/mathematics.haifa.ac.il\/?p=764"},"modified":"2017-04-10T11:26:37","modified_gmt":"2017-04-10T08:26:37","slug":"colloquium-tuesday-april-4-2-pm-speaker-alex-lubotzky-hebrew-university-title-first-order-rigidity-of-high-rank-arithmetic-groups","status":"publish","type":"post","link":"https:\/\/mathematics.haifa.ac.il\/?p=764","title":{"rendered":"Colloquium: Tuesday, April 4, 2 pm. Speaker: Alex Lubotzky (Hebrew University). Title: &#8220;First order rigidity of high-rank arithmetic groups&#8221;."},"content":{"rendered":"<p>The family of high rank arithmetic groups is class of groups which is playing\u00a0 an important role in various areas of mathematics. It includes SL(n,Z) for n&gt;2, SL(n, Z[1\/p]) for n&gt;1, their finite index subgroups and many more. A number of remarkable results on them have been proven, including: Mostow rigidity, Margulis super rigidity and the Quasi-isometric rigidity.<\/p>\n<p>We will talk about a new type of rigidity (which at this point we can prove only for many but not all): first order rigidity. Namely if G is such an arithmetic group and H a finitely generated group which is elementary equivalent to it (i.e., the same first order theory in the sense of model theory) then H is isomorphic to G. This stands in contrast with Zlil Sela&#8217;s remarkable work which implies that the free groups, surface groups and hyperbolic groups (many of whose are low-rank arithmetic groups) are far from having such a rigidity.<\/p>\n<p>Various questions and problems for further research will be discussed.<\/p>\n<p>Joint work (in progress) with Nir Avni and Chen Meiri.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The family of high rank arithmetic groups is class of groups which is playing\u00a0 an important role in various areas of mathematics. It includes SL(n,Z) for n&gt;2, SL(n, Z[1\/p]) for n&gt;1, their finite index subgroups and many more. A number&#8230;<br \/><a class=\"read-more-button\" href=\"https:\/\/mathematics.haifa.ac.il\/?p=764\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-764","post","type-post","status-publish","format-standard","hentry","category-colloquium"],"_links":{"self":[{"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/posts\/764","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=764"}],"version-history":[{"count":1,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/posts\/764\/revisions"}],"predecessor-version":[{"id":765,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/posts\/764\/revisions\/765"}],"wp:attachment":[{"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=764"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=764"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=764"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}