{"id":277,"date":"2012-03-17T23:41:28","date_gmt":"2012-03-17T23:41:28","guid":{"rendered":"http:\/\/geometry.ma.ic.ac.uk\/seminar\/?page_id=277"},"modified":"2014-09-28T20:04:43","modified_gmt":"2014-09-28T20:04:43","slug":"summer-2012","status":"publish","type":"page","link":"http:\/\/coates.ma.ic.ac.uk\/seminar\/?page_id=277","title":{"rendered":"Summer Term 2012"},"content":{"rendered":"

 
\nVarious speakers. <\/em>Geometry Day III. <\/strong> Friday May 4th. King’s College London.<\/p>\n

Geometry Day III will be taking place on 4 May 2012 in K0.16, King’s Building, Strand Campus of King’s College London.
\nSpeakers are: Simon Donaldson, Francisco Lopez, Baris Coskunuzer, Carlo Sinestrari and YanYan Li.<\/p>\n

If you would like to attend, please contact Emily Balls (emily.balls@kcl.ac.uk) with your name, email address and institution, ideally by 20 April 2012. Please also indicate whether you are interested in attending the dinner for which there will be a nominal fee. Any academic questions should be directed to Dr Giuseppe Tinaglia (giuseppe.tinaglia@kcl.ac.uk).<\/p>\n

More information at www.kcl.ac.uk\/nms\/depts\/mathematics\/geometry3.aspx<\/a><\/p>\n


\nMarc Lackenby (Oxford). <\/em>Links with splitting number one. <\/strong> Friday May 11th. Huxley 139, 1.30-2.30pm.<\/p>\n

The unknotting number of a knot is an incredibly difficult invariant to compute. In fact, there are many knots which are conjectured to have unknotting number 2 but for which no proof of this is currently available. It therefore remains an unsolved problem to find an algorithm that determines whether a knot has unknotting number one. In my talk, I will show that an analogous problem for links is soluble. We say that a link has splitting number one if some crossing change turns it into a split link. I will give an algorithm that determines whether a link has splitting number one. (In the case where the link has two components, we must make a hypothesis on their linking number.) The proof that the algorithm works uses sutured manifolds and normal surfaces.<\/p>\n


\nGabor Szekelyhidi (University of Notre Dame)<\/em>. Filtrations and test-configurations.<\/strong>\u00a0Friday May 18th. Huxley 139, 1.30-2.30pm.<\/p>\n

Test-configurations are certain degenerations of projective manifolds, which are used in the definition of K-stability. I will explain how filtrations of the homogeneous coordinate ring of a projective manifold can be thought of as sequences of test-configurations, and that they encode the limiting behavior of these sequences. These filtrations arise naturally when studying the Calabi flow, or when trying to minimize the Calabi functional. I will also discuss how filtrations can be used to give a strengthening of the notion of K-stability, and why this is desirable.<\/p>\n


\nJan Christophersen (University of Oslo)<\/em>. Simplicial complexes and projective varieties.<\/strong> Friday May 25th. Huxley 139, 1.30-2.30pm.<\/p>\n

The Stanley-Reisner construction associates to a simplicial complex a projective scheme which “looks like” the complex. For combinatorial manifolds, if the scheme is smoothable, it will smooth to special algebraic varieties. For example a sphere will in this way correspond to a Calabi-Yau manifold and a torus to an abelian variety. It turns out that interesting triangulations of manifolds yield interesting algebraic geometry via deformations of Stanley-Reisner schemes and I will describe this connection with several examples.<\/p>\n


\nNo Seminar. <\/em><\/strong>\u00a0Friday June 1st.
\n<\/p>\n

Roger Bielawski (Leeds). <\/em>Pluricomplex geometry and quaternionic manifolds.<\/strong> Friday June 8th. Huxley 139, 1.30-2.30pm.<\/p>\n

I will describe a new type of geometric structure on complex manifolds. It can be viewed as a deformation of hypercomplex structure, but it also leads to a special type of hypercomplex and hyperk\u00e4hler geometry. These structures have both algebro-geometric and differential-geometric descriptions, and there are interesting examples arising from physics. Moreover, a class of pluricomplex manifolds leads to quaternion-K\u00e4hler metrics, generalising the SO(3)-invariant self-dual Einstein examples of Hitchin.<\/p>\n


\nMarion Moore Campisi (University of Texas, Austin). <\/em>Bridge distance and exceptional surgeries.<\/strong>\u00a0Friday June 15th. Huxley 340, 1.30-2.30pm.<\/p>\n

In this talk I will discuss ongoing work which shows that links that have high distance bridge surfaces do not admit exceptional surgeries. The distance d(T) of a bridge surface T is defined in terms of the arc and curve complex for the bridge surface and has become a standard way of measuring the “complexity” of the link. This is joint work with Ryan Blair, Jesse Johnson, Scott Taylor and Maggy Tomova.
\n
\nAndrea Brini (Imperial). <\/em>A crepant resolution conjecture for open strings.<\/strong> Friday June 22nd. Huxley 139, 1.30-2.30pm.<\/p>\n

We propose a Crepant Resolution Conjecture in the context of open Gromov-Witten theory. The content of this talk is based on arxiv:1102.0281 and on joint work in progress with R. Cavalieri (CSU), T. Coates (Imperial) and D. Ross (CSU).<\/p>\n


\nAnne-Sophie Kaloghiros (Imperial). <\/em>Geography of models and the Sarkisov Program.<\/strong> Friday June 29th. Huxley 139, 1.30-2.30pm.<\/p>\n

Given a normal projective variety X and an effective divisor D on X, an important question is to determine whether X has a “good model” for D. When does there exist a birational map X–>X_D, where X_D has manageable singularities and where f_*D is “positive” in a suitable sense? This question can be answered for two remarkable classes of varieties and divisors on them: the first is that of varieties where the Minimal Model Program can be run, and the other that of Mori Dream Spaces. I will define a class that generalizes these two examples, and show how to understand birational maps between good models for distinct divisors. I will give an application to the study of birational maps between Mori fibre spaces (the Sarkisov Program): I will describe generators (work of Hacon-McKernan) and relations in the Sarkisov Program. Part of this talk is based on joint work with Kuronya and Lazic.<\/p>\n


\nVincent Borrelli (Lyon)<\/em> and Etienne Ghys (CNRS, Lyon).<\/em> LMS Hardy Lecture.<\/strong> Friday June 29th. University College London, 3.30-6.30pm.<\/p>\n

Vincent Borrelli will speak on Flat tori in three-dimensional space<\/em> at 3.30, and Etienne Ghys will speak on Cutting cloth according to Chebyshev<\/em> at 5.15. Both talks will be directed at a general mathematical audience. A reception will follow at 6.30 at a cost of \u00a335 per person. See http:\/\/www.lms.ac.uk\/sites\/default\/files\/files\/posters\/Hardy%2012%20poster.pdf<\/a> for more details and for contact information.<\/p>\n","protected":false},"excerpt":{"rendered":"

  Various speakers. Geometry Day III. Friday May 4th. King’s College London. Geometry Day III will be taking place on 4 May 2012 in K0.16, King’s Building, Strand Campus of King’s College London. Speakers are: Simon Donaldson, Francisco Lopez, Baris Coskunuzer, Carlo Sinestrari and YanYan Li. If you would like to attend, please contact Emily …<\/p>\n

Continue reading ‘Summer Term 2012’ »<\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"parent":0,"menu_order":35,"comment_status":"open","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-277","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"http:\/\/coates.ma.ic.ac.uk\/seminar\/index.php?rest_route=\/wp\/v2\/pages\/277","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/coates.ma.ic.ac.uk\/seminar\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/coates.ma.ic.ac.uk\/seminar\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/coates.ma.ic.ac.uk\/seminar\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"http:\/\/coates.ma.ic.ac.uk\/seminar\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=277"}],"version-history":[{"count":60,"href":"http:\/\/coates.ma.ic.ac.uk\/seminar\/index.php?rest_route=\/wp\/v2\/pages\/277\/revisions"}],"predecessor-version":[{"id":789,"href":"http:\/\/coates.ma.ic.ac.uk\/seminar\/index.php?rest_route=\/wp\/v2\/pages\/277\/revisions\/789"}],"wp:attachment":[{"href":"http:\/\/coates.ma.ic.ac.uk\/seminar\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=277"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}