{"id":1377,"date":"2019-02-24T11:10:53","date_gmt":"2019-02-24T09:10:53","guid":{"rendered":"https:\/\/mathematics.haifa.ac.il\/?p=1377"},"modified":"2019-03-01T12:05:07","modified_gmt":"2019-03-01T10:05:07","slug":"this-thursday-at-u-haifa-topology-geometry-seminar-on-february-28-2019-at-1210","status":"publish","type":"post","link":"https:\/\/mathematics.haifa.ac.il\/?p=1377","title":{"rendered":"This Thursday at U. Haifa Topology &#038; Geometry seminar on February 28, 2019 at 12:10"},"content":{"rendered":"<p style=\"font-weight: 400;\"><strong><u>Geometry\u00a0&amp; Topology Seminar<\/u><\/strong><\/p>\n<p style=\"font-weight: 400;\">Speaker:\u00a0\u00a0Shachar Carmeli\u00a0\u00a0(The Weizmann Institute of Science)<\/p>\n<p style=\"font-weight: 400;\">Topic:\u00a0\u00a0Etale Obstructions to Rational Points on Arithmetic Spheres<\/p>\n<p style=\"font-weight: 400;\">Place:\u00a0\u00a0\u00a0 room 614 in the Science &amp; Education Building<\/p>\n<p style=\"font-weight: 400;\">Time\u00a0 \u00a012:10<\/p>\n<p style=\"font-weight: 400;\">Date:\u00a0 Thursday, February 28, 2019<\/p>\n<p style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<strong><u>Abstract<\/u><\/strong><strong><u>:<\/u><\/strong><\/p>\n<p>Etale homotopy theory attaches to every algebraic variety X over a field F a homotopy type E&#8217;t(X) called the etale homotopy type.<\/p>\n<p>This construction was generalized by Schlank and Barnea to the relative case, and attached with every algebraic variety over X a sequence of obstructions to rational points leaving in certain Galois cohomology groups.<\/p>\n<p>I will introduce relative etale homotopy theory from an infinity-categorical perspective, and the relevant obstruction theory. Then I will present our computation of the (mod 2) lowest obstruction to solutions of quadratic equations in many variables over F.\u00a0 This is a joint work with Edo Arad and Tomer Schlank.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Geometry\u00a0&amp; Topology Seminar Speaker:\u00a0\u00a0Shachar Carmeli\u00a0\u00a0(The Weizmann Institute of Science) Topic:\u00a0\u00a0Etale Obstructions to Rational Points on Arithmetic Spheres Place:\u00a0\u00a0\u00a0 room 614 in the Science &amp; Education Building Time\u00a0 \u00a012:10 Date:\u00a0 Thursday, February 28, 2019 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Abstract: Etale homotopy theory attaches to every&#8230;<br \/><a class=\"read-more-button\" href=\"https:\/\/mathematics.haifa.ac.il\/?p=1377\">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":[6,4],"tags":[],"class_list":["post-1377","post","type-post","status-publish","format-standard","hentry","category-gt-seminar","category-seminar"],"_links":{"self":[{"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/posts\/1377","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=1377"}],"version-history":[{"count":2,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/posts\/1377\/revisions"}],"predecessor-version":[{"id":1387,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/posts\/1377\/revisions\/1387"}],"wp:attachment":[{"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1377"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1377"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1377"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}