{"id":4725,"date":"2023-01-26T09:37:30","date_gmt":"2023-01-26T14:37:30","guid":{"rendered":"http:\/\/matroidunion.org\/?p=4725"},"modified":"2023-02-03T07:49:18","modified_gmt":"2023-02-03T12:49:18","slug":"online-talk-tom-zaslavsky","status":"publish","type":"post","link":"https:\/\/matroidunion.org\/?p=4725","title":{"rendered":"Online Talk: Tom Zaslavsky"},"content":{"rendered":"\n<p><strong>YouTube recording:\u00a0<\/strong><a href=\"https:\/\/youtu.be\/UdjhEgSKQus\" target=\"_blank\" rel=\"noopener\">https:\/\/youtu.be\/UdjhEgSKQus<\/a><strong><br \/><br \/>Time: <\/strong>Thursday, Feb 2, 3pm EST (8pm GMT, 9am Fri NZDT)<br \/><strong>Zoom: <\/strong><a href=\"https:\/\/gatech.zoom.us\/j\/8802082683\">https:\/\/gatech.zoom.us\/j\/8802082683<\/a><br \/><br \/><strong>Speaker:<\/strong> <a href=\"https:\/\/www2.math.binghamton.edu\/p\/people\/zaslav\/start\" target=\"_blank\" rel=\"noopener\">Tom Zaslavsky<\/a>, Binghamton University<br \/><strong>Title:\u00a0<\/strong>Matroids of gain signed graphs<br \/><strong>Abstract: <\/strong>For standard affinographic hyperplane arrangements (a.k.a. deformations of<br aria-hidden=\"true\" \/>the Type A root system arrangement or &#8220;braid&#8221; arrangement), integral gain<br aria-hidden=\"true\" \/>graphs give a simpler method to compute the characteristic polynomial, a<br aria-hidden=\"true\" \/>fundamental invariant.\u00a0 For more general affinographic arrangements<br aria-hidden=\"true\" \/>(a.k.a. deformations of the Type B root system arrangement), one has to<br aria-hidden=\"true\" \/>combine gains with signs.\u00a0 How to do this has been a puzzle.\u00a0 The obvious<br aria-hidden=\"true\" \/>method is to put signs on top of gains.\u00a0 The right method is to put gains<br aria-hidden=\"true\" \/>on top of signs.\u00a0 Laura Anderson, Ting Su, and I found out how to do this,<br aria-hidden=\"true\" \/>constructing the natural matroid and the corresponding semimatroid, which<br aria-hidden=\"true\" \/>latter gives the characteristic polynomial of these more general<br aria-hidden=\"true\" \/>arrangements when the gain group is the additive group of integers.\u00a0 I<br aria-hidden=\"true\" \/>will explain some of this.\u00a0 It does get complicated.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>YouTube recording:\u00a0https:\/\/youtu.be\/UdjhEgSKQus Time: Thursday, Feb 2, 3pm EST (8pm GMT, 9am Fri NZDT)Zoom: https:\/\/gatech.zoom.us\/j\/8802082683 Speaker: Tom Zaslavsky, Binghamton UniversityTitle:\u00a0Matroids of gain signed graphsAbstract: For standard affinographic hyperplane arrangements (a.k.a. deformations ofthe Type A root system arrangement or &#8220;braid&#8221; arrangement), integral &hellip; <a href=\"https:\/\/matroidunion.org\/?p=4725\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":21,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[11],"class_list":["post-4725","post","type-post","status-publish","format-standard","hentry","category-matroids","tag-online-talks"],"_links":{"self":[{"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/posts\/4725","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/users\/21"}],"replies":[{"embeddable":true,"href":"https:\/\/matroidunion.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4725"}],"version-history":[{"count":3,"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/posts\/4725\/revisions"}],"predecessor-version":[{"id":4739,"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/posts\/4725\/revisions\/4739"}],"wp:attachment":[{"href":"https:\/\/matroidunion.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4725"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/matroidunion.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4725"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/matroidunion.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4725"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}