BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Denis Auroux (Harvard University) DTSTART:20210413T150000Z DTEND:20210413T160000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/1 DESCRIPTION:Title: An invitation to homological mirror symmetry\nby Deni s Auroux (Harvard University) as part of Kolloquium über Reine Mathematik Universität Hamburg\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Sergei Merkulov (Université du Luxembourg) DTSTART:20210427T150000Z DTEND:20210427T160000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/2 DESCRIPTION:Title: On the classification of Kontsevich formality maps\nb y Sergei Merkulov (Université du Luxembourg) as part of Kolloquium über Reine Mathematik Universität Hamburg\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Bernardo Uribe Jongbloed (Universidad del Norte in Barranquilla) DTSTART:20210511T150000Z DTEND:20210511T160000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/3 DESCRIPTION:Title: Pontrjagin duality on multiplicative gerbes\nby Berna rdo Uribe Jongbloed (Universidad del Norte in Barranquilla) as part of Kol loquium über Reine Mathematik Universität Hamburg\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Vincent Pecastaing (Université Côte d'Azur) DTSTART:20210525T150000Z DTEND:20210525T160000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/4 DESCRIPTION:Title: Rigidity of higher-rank lattices actions\nby Vincent Pecastaing (Université Côte d'Azur) as part of Kolloquium über Reine Ma thematik Universität Hamburg\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Bruno Klingler (HU Berlin) DTSTART:20210608T150000Z DTEND:20210608T160000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/5 DESCRIPTION:Title: Tame geometry and Hodge theory\nby Bruno Klingler (HU Berlin) as part of Kolloquium über Reine Mathematik Universität Hamburg \n\n\nAbstract\nHodge theory\, as developed by Deligne and Griffiths\, is one of the main tool for analyzing the geometry and arithmetic of complex algebraic varieties\, that is\, solution sets of algebraic equations over the complex numbers. It is an essential fact that at heart\, Hodge theory is not algebraic but rather transcendent. I will try to describe how tame geometry\, whose idea was introduced by Grothendieck in the 1980s and was developed by model theorist as o-minimal geometry\, seems to be the natur al framework to control this transcendence.\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Mark Gross (Cambridge University) DTSTART:20210622T150000Z DTEND:20210622T160000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/6 DESCRIPTION:Title: Intrinsic Mirror Symmetry\nby Mark Gross (Cambridge U niversity) as part of Kolloquium über Reine Mathematik Universität Hambu rg\n\n\nAbstract\nMirror symmetry was a phenomenon discovered by physicist s around 1989: they observed that certain kinds of six-dimensional geometr ic objects known as Calabi-Yau manifolds seemed to come in pairs\, with a strange relationship between different kinds of geometric objects on the p airs. Since then\, the subject has blossomed into a vast field\, with many different approaches and philosophies. I will give a brief introduction t o the subject\, and explain how one of these approaches\, developed with B ernd Siebert\, has led to a general construction of mirror pairs.\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Philip Boalch (Jussieu) DTSTART:20210629T150000Z DTEND:20210629T160000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/7 DESCRIPTION:Title: Diagrams\, wild nonabelian Hodge spaces and global Lie th eory\nby Philip Boalch (Jussieu) as part of Kolloquium über Reine Mat hematik Universität Hamburg\n\n\nAbstract\nThe classical theory of system s of linear differential equations in the complex domain morphed\ninto the theory of connections on curves\, and then morphed again into "2d gauge t heory"\, a highpoint\nbeing the nonabelian Hodge theorem of Hitchin-Simpso n-Corlette-Donaldson.\nHowever along the way\, a sleight of hand was done: the passage to compact Riemann surfaces\,\nthereby avoiding the tricky pr oblem of understanding boundary conditions on noncompact Riemann\nsurfaces . The good news is that these tricky problems were solved by mathematician s working in France some 20 years ago\, a key step being to understand the classical papers on irregular singularities.\nThis led to the wild nonabe lian Hodge theorem on curves\, and a huge bestiary of new complete\nhyperk ahler manifolds\, now encompassing the classical examples of integrable sy stems stemming\nfrom work of Painleve\, Schlesinger\, Garnier\, Moser\, Mu mford\, Seiberg-Witten and others. In this\ntalk I'll review/describe some of the simplest examples\, sketch how to describe them topologically in t erms of Stokes local systems (generalising the usual fundamental group rep resentations) and recent steps to define a theory of ``Dynkin diagrams'' t o classify these new nonabelian Hodge moduli spaces.\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Maryna Viazovska (EPF Lausanne) DTSTART:20210706T150000Z DTEND:20210706T163000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/9 DESCRIPTION:Title: The Leech Lattice\nby Maryna Viazovska (EPF Lausanne) as part of Kolloquium über Reine Mathematik Universität Hamburg\n\n\nAb stract\nThis lecture is about a magical mathematical object -- the Leech l attice. We will speak about the history of its discovery\, its connections to coding theory\, and the role of the Leech lattice in the search for sp oradic simple groups. Also we will speak about extremal properties of Leec h lattice and its connections to other extremal geometric and combinatoria l structures.\n\nRegister your email for the Gauß-Vorlesung in the sectio n "6. Juli 2021 Augsburg (online)" on https://www.mathematik.de/dmv/gauss- vorlesungen\n\nThere is a pre-talk by Juergen Richter-Gebert about "Spazie rgaenge in der vierten Dimension"\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Nitya Kitchloo (Johns Hopkins University) DTSTART:20211130T170000Z DTEND:20211130T180000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/10 DESCRIPTION:Title: Symmetry breaking and homotopy types for Link homologie< /a>\nby Nitya Kitchloo (Johns Hopkins University) as part of Kolloquium ü ber Reine Mathematik Universität Hamburg\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Ana Caraiani (Imperial College London) DTSTART:20220104T160000Z DTEND:20220104T170000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/11 DESCRIPTION:Title: Reciprocity laws and torsion classes\nby Ana Caraian i (Imperial College London) as part of Kolloquium über Reine Mathematik U niversität Hamburg\n\n\nAbstract\nThe Langlands program is a vast network of conjectures that connect many areas of pure mathematics\, such as numb er theory\, representation theory\, and harmonic analysis. At its heart li es reciprocity\, the conjectural relationship between Galois representatio ns and modular\, or automorphic forms.\n\nA famous instance of reciprocity is the modularity of elliptic curves over the rational numbers: this was the key to Wiles’s proof of Fermat’s last theorem. I will give an over view of some recent progress in the Langlands program\, with a focus on ne w reciprocity laws over imaginary quadratic fields.\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Alastair King (University of Bath) DTSTART:20220111T160000Z DTEND:20220111T170000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/12 DESCRIPTION:Title: Categorification of perfect matchings\nby Alastair K ing (University of Bath) as part of Kolloquium über Reine Mathematik Univ ersität Hamburg\n\n\nAbstract\nI will explain how treating perfect matchi ngs as modules leads to improved understanding of some of the combinatoric s of Grassmannian cluster algebras\, which I will also explain. General kn owledge about cluster algebras will not be assumed (or required).\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Petra Schwer (OVGU Magdeburg) DTSTART:20220118T160000Z DTEND:20220118T170000Z DTSTAMP:20260422T215119Z UID:UHH-pure-math-Kolloquium/13 DESCRIPTION:Title: Building bridges between Geometry and Algebra\nby Pe tra Schwer (OVGU Magdeburg) as part of Kolloquium über Reine Mathematik U niversität Hamburg\n\n\nAbstract\nDisclaimer: This talk is meant to be ac cessible. So don't shy away because of unfamiliar words.\n\nGroups like GL _n\, SL_n or SP_n play an important role in many areas of mathematics. It has bee known for a long time that some of their properties (when studied over the reals or complex numbers) are best understood via the associated symmetric spaces. Jaques Tits later introduced buildings as a tool to stu dy the respective groups over other field and developed\, together with Br uhat\, a theory that also captures reductive groups evaluated over non-arc himedian local fields with discrete valuation\, like the p-adic numbers.\n \nIn this talk I will explain how some of the subgroup structures of such a reductive group over a non-Archimedian local field can be explained via Coxeter combinatorics and the geometry of an (affine) Bruhat-Tits building \, its apartments and retractions. The building for example simultaneously encodes the (affine) flag variety and (affine) Grassmannian associated to the group. But it also permits to explain more complicated structures suc h as representation theoretic data or other associated varieties in purely combinatorial terms.\n\nThe underlying structure of a building is Coxeter groups and their associated Coxeter complex. A simplicial complex on whic h the groups act in a good way. We will discuss some of the combinatorial properties of Coxeter groups and buildings and explain how they can be use d to study varieties attached to the mentioned algebraic groups. We will d o so by looking at two examples: nonemptiness and dimensions of affine De ligne Lusztig varieties (ADLVs) can be computed with the help of Coxeter g roup combinatorics. The ADLVs are sub-varieties of the affine flag variety of an algebraic group. And their nonemptiness can be stated in terms of g alleries and their retracted images in the associated Bruhat-Tits building . In addition we will talk about the problem of exact computation of refle ction length in affine Coxeter groups. Here reflection length means the mi nimal number of elements needed to write a given element as a product of r eflections. Surprisingly this notion is closely related to dimensions of a n ADLV.\n LOCATION:https://researchseminars.org/talk/UHH-pure-math-Kolloquium/13/ END:VEVENT END:VCALENDAR