{"id":25914,"date":"2025-11-12T18:32:29","date_gmt":"2025-11-12T15:32:29","guid":{"rendered":"https:\/\/w3.bilkent.edu.tr\/en\/?p=25914"},"modified":"2025-11-16T23:58:41","modified_gmt":"2025-11-16T20:58:41","slug":"math-seminar-brill-noether-theory-for-vector-bundles-on-surfaces-neelarnab-raha-600pm-november-14-2025-en","status":"publish","type":"post","link":"https:\/\/w3.bilkent.edu.tr\/en\/math-seminar-brill-noether-theory-for-vector-bundles-on-surfaces-neelarnab-raha-600pm-november-14-2025-en\/","title":{"rendered":"MATH Seminar: \u201cBrill-Noether theory for vector bundles on surfaces\u201d, Neelarnab Raha, 6:00PM November 14 2025 (EN)"},"content":{"rendered":"<p>You are cordially invited to the seminars organized by the Department of Mathematics.<\/p>\n<p>Speaker: Neelarnab Raha (Penn State)<\/p>\n<p>\u201cBrill-Noether theory for vector bundles on surfaces\u201d<\/p>\n<p>Abstract: The Brill-Noether theory of curves plays a fundamental role in the theory of curves and their moduli and has been intensively studied since the 19th century. In contrast, Brill-Noether theory for higher dimensional varieties is less understood. It is hard to determine when Brill-Noether loci are nonempty, and these loci can be reducible and of larger than the expected dimension.<\/p>\n<pre><code>  Let $E$ be a semistable vector bundle on the projective plane. We give an upper bound $\\beta_{r,\\mu}$ for $h^0(E)$ in terms of the rank $r$ and the slope $\\mu$ of $E$. We show that the bound is achieved precisely when $E$ is a Steiner bundle. We classify those $E$ for which $h^0(E)$ is close to $\\beta_{r,\\mu}$. We determine the nonemptiness, irreducibility and dimension of the Brill-Noether loci with $h^0(E)$ in this range. When they are proper subvarieties, these Brill-Noether loci are irreducible though almost always of larger than the expected dimension. This is joint work with Professors Izzet Coskun and Jack Huizenga.\r\n\r\n  We also have a similar bound on the smooth quadric surface, although it is more subtle depending on how balanced the first Chern class is, and what global generation properties the vector bundle possesses.\r\n<\/code><\/pre>\n<p>Date: November 14, Friday<br \/>\nTime: 6:00 P.M. (Turkey)<br \/>\nPlace: Zoom<\/p>\n<p>To request the event link, please send a message to turker.ozsari@bilkent.edu.tr<\/p>\n","protected":false},"excerpt":{"rendered":"<p>You are cordially invited to the seminars organized by the Department of Mathematics. Speaker: Neelarnab Raha (Penn State) \u201cBrill-Noether theory for vector bundles on surfaces\u201d Abstract: The Brill-Noether theory of curves plays a fundamental role in the theory of curves and their moduli and has been intensively studied since the [\u2026] <\/p>\n<div class=\"clear\"><\/div>\n<p><a class=\"more_link clearfix\" href=\"https:\/\/w3.bilkent.edu.tr\/en\/math-seminar-brill-noether-theory-for-vector-bundles-on-surfaces-neelarnab-raha-600pm-november-14-2025-en\/\" rel=\"nofollow\">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":[12],"tags":[],"class_list":["post-25914","post","type-post","status-publish","format-standard","hentry","category-oldposts"],"_links":{"self":[{"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/posts\/25914","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/comments?post=25914"}],"version-history":[{"count":1,"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/posts\/25914\/revisions"}],"predecessor-version":[{"id":25915,"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/posts\/25914\/revisions\/25915"}],"wp:attachment":[{"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/media?parent=25914"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/categories?post=25914"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/w3.bilkent.edu.tr\/en\/wp-json\/wp\/v2\/tags?post=25914"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}