{"id":1620,"date":"2019-12-30T14:28:55","date_gmt":"2019-12-30T12:28:55","guid":{"rendered":"https:\/\/mathematics.haifa.ac.il\/?p=1620"},"modified":"2020-01-08T18:26:01","modified_gmt":"2020-01-08T16:26:01","slug":"this-week-thursday-at-1000-u-haifa-topology-geometry-seminar-on-january-2-2020","status":"publish","type":"post","link":"https:\/\/mathematics.haifa.ac.il\/?p=1620","title":{"rendered":"This week, Thursday at 10:00, U. Haifa Topology &#038; Geometry seminar on January 2, 2020"},"content":{"rendered":"<p><strong><u>Geometry\u00a0&amp; Topology Seminar<\/u><\/strong><\/p>\n<p>Speaker:\u00a0\u00a0Liat Kessler\u00a0(Oranim Academic College)<\/p>\n<p>Topic:\u00a0\u00a0Equivariant cohomology does not distinguish Hamiltonian S^1-manifolds<\/p>\n<p>Place:\u00a0 Room 614 in the Science &amp; Education Building<\/p>\n<p>Time:\u00a0 \u00a010:00<\/p>\n<p>Date:\u00a0 Thursday, January 2,\u00a0 2020<\/p>\n<p>&nbsp;<\/p>\n<p><strong><u>Abstract<\/u><\/strong><strong><u>:<\/u><\/strong><\/p>\n<p style=\"font-weight: 400;\">For Hamiltonian circle actions on 4-manifolds, we give an example of an isomorphism of equivariant cohomology modules that cannot be induced by an equivariant diffeomorphism of spaces. This is in contrast to Masuda\u2019s result establishing that in the toric case, the equivariant cohomology module determines the manifold. We also give a soft proof that there are finitely many maximal Hamiltonian circle actions on a fixed closed symplectic 4-manifold.<\/p>\n<p style=\"font-weight: 400;\">We achieve these results by giving a generators and relations description in terms of the decorated graph for the even part of the equivariant cohomology as a module over the equivariant cohomology of a point.\u00a0We then give an explicit combinatorial description of all weak algebra isomorphisms.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Geometry\u00a0&amp; Topology Seminar Speaker:\u00a0\u00a0Liat Kessler\u00a0(Oranim Academic College) Topic:\u00a0\u00a0Equivariant cohomology does not distinguish Hamiltonian S^1-manifolds Place:\u00a0 Room 614 in the Science &amp; Education Building Time:\u00a0 \u00a010:00 Date:\u00a0 Thursday, January 2,\u00a0 2020 &nbsp; Abstract: For Hamiltonian circle actions on 4-manifolds, we give&#8230;<br \/><a class=\"read-more-button\" href=\"https:\/\/mathematics.haifa.ac.il\/?p=1620\">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-1620","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\/1620","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=1620"}],"version-history":[{"count":1,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/posts\/1620\/revisions"}],"predecessor-version":[{"id":1621,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=\/wp\/v2\/posts\/1620\/revisions\/1621"}],"wp:attachment":[{"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1620"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1620"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mathematics.haifa.ac.il\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1620"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}