Calendar – University of Copenhagen

Forward this page to a friend Resize Print kalender-ikon Bookmark and Share

Symmetry and Deformation > Calendar

Calendar

Events at the Centre for Symmetry and Deformation.

  • 2 May 2017, 15:15-16:15

    Algebra/Topology Seminar by Joachim Kock

    Talk by Joachim Kock (Universitat Autònoma de Barcelona) Title: Decomposition spaces, incidence algebras, and Möbius inversion Abstract: I'll survey recent work with Imma Gálvez and Andy Tonks developing a homotopy version of the theory of incidence algebras and Möbius inversion.  The 'combinatorial objects' playing the role of posets and Möbius categories are decomposition spaces, simplicial infinity-groupoids satisfying an exactness condition weaker than the Segal condition, expressed in terms of generic and free maps in Delta.  Just as the Segal condition expresses up-to-homotopy composition, the new condition expresses decomposition.  The role of vector spaces is played by slices over infinity-groupoids, eventually with homotopy finiteness conditions imposed.  To any decomposition space, there is associated an incidence (co)algebra with coefficients in infinity-groupoids, which satisfies an objective Möbius inversion principle in the style of Lawvere-Menni, provided a certain completeness condition is satisfied, weaker than the Rezk condition.  Generic examples of decomposition spaces beyond Segal spaces are given by the Waldhausen S-construction (yielding Hall algebras) and by Schmitt restriction species, and many examples from classical combinatorics admit uniform descriptions in this framework.(The notion of decomposition space is equivalent to the notionof unital 2-Segal space of Dyckerhoff-Kapranov.) » Read more

  • 8 May - 11 May 2017

    Masterclass: Cohomology of arithmetic groups

    The Masterclass will consist of two lecture series by Andy Putman and Harald Grobner, as well as a number of contributed talks about current research. See here for more information. » Read more

  • 8 May 2017, 10:00-11:00

    Masterclass Lecture by Andy Putman

    Lecture in Masterclass: Cohomology of arithmetic groups by Andy Putman (Notre Dame) Title: Buildings, duality, and the high-dimensional cohomology of arithmetic groups Abstract: I will discuss topological results about the cohomology of arithmetic groups, focusing for simplicity on the group SL(n,Z). Topics include the Borel-Serre bordification, Bieri-Eckmann duality, the structure of the Steinberg module, and the high-dimensional cohomology of these groups. » Read more

  • 8 May 2017, 11:30-12:30

    Masterclass Lecture by Harald Grobner

    Lecture in Masterclass: Cohomology of arithmetic groups by Harald Grobner (Universität Wien) Title: Cohomological automorphic forms: A survey based on examples. Abstract: In this lecture series we will study the cohomology of arithmetic groups through the theory of automorphic forms. Firstly conjectured by A. Borel and G. Harder, the cohomology H^q(Γ, E) of an arithmetic (congruence) subgroup Γ of a connected reductive group G is isomorphic to the relative Lie algebra cohomology of a space of automorphic forms on G. It is really due to epoch-making work of J. Franke that this identication of group-cohomology and automorphic cohomology is now known in full generality. This connection of automorphic forms with the cohomology of arithmetic groups is the deep source of a highly interesting mélange of ideas, approaches and moreover possible applications. It turns out that cohomological automorphic forms i.e., automorphic forms contributing to the cohomology H^q(Γ, E) of some arithmetic group Γ as above play the key role in an extremely rich area of mathematical problems: To mention one of their highlights, the analysis of ζ-functions and their generalizations. This lecture series will (try to) put a spotlight on (i) the problems connected with the very study of H^q(Γ, E) by cohomological automorphic forms, as well as (ii) on some of the far-reaching applications, mentioned above. As the title suggests, we will do this based on a selection of interesting examples, while we try to avoid the huge backlock of the general theory. » Read more

  • 8 May 2017, 15:15-16:15

    Algebra/Topology Seminar by Herbert Gangl

    Talk by Herbert Gangl (Durham University) Title and Abstract: TBA » Read more

  • 9 May 2017, 10:00-11:00

    Masterclass Lecture II by Andy Putman

    Lecture in Masterclass: Cohomology of arithmetic groups by Andy Putman (Notre Dame) Title: Buildings, duality, and the high-dimensional cohomology of arithmetic groups Abstract: I will discuss topological results about the cohomology of arithmetic groups, focusing for simplicity on the group SL(n,Z). Topics include the Borel-Serre bordification, Bieri-Eckmann duality, the structure of the Steinberg module, and the high-dimensional cohomology of these groups. » Read more

  • 9 May 2017, 11:30-12:30

    Masterclass Lecture II by Harald Grobner

    Lecture in Masterclass: Cohomology of arithmetic groups by Harald Grobner (Universität Wien) Title: Cohomological automorphic forms: A survey based on examples. Abstract: In this lecture series we will study the cohomology of arithmetic groups through the theory of automorphic forms. Firstly conjectured by A. Borel and G. Harder, the cohomology H^q(Γ, E) of an arithmetic (congruence) subgroup Γ of a connected reductive group G is isomorphic to the relative Lie algebra cohomology of a space of automorphic forms on G. It is really due to epoch-making work of J. Franke that this identication of group-cohomology and automorphic cohomology is now known in full generality. This connection of automorphic forms with the cohomology of arithmetic groups is the deep source of a highly interesting mélange of ideas, approaches and moreover possible applications. It turns out that cohomological automorphic forms i.e., automorphic forms contributing to the cohomology H^q(Γ, E) of some arithmetic group Γ as above play the key role in an extremely rich area of mathematical problems: To mention one of their highlights, the analysis of ζ-functions and their generalizations. This lecture series will (try to) put a spotlight on (i) the problems connected with the very study of H^q(Γ, E) by cohomological automorphic forms, as well as (ii) on some of the far-reaching applications, mentioned above. As the title suggests, we will do this based on a selection of interesting examples, while we try to avoid the huge backlock of the general theory. » Read more

  • 9 May 2017, 14:00-15:00

    Masterclass Lecture by Orsola Tommasi

    Lecture in Masterclass: Cohomology of arithmetic groups by Orsola Tommasi (Chalmers University of Technology and University of Gothenburg) Title: Cohomological stabilization of toroidal compactifications of A_gAbstract: By a classical result of Borel, the cohomology of the symplectic group Sp(2g,Z) stabilizes in degree k » Read more

  • 10 May 2017, 10:00-11:00

    Masterclass Lecture III by Andy Putman

    Lecture in Masterclass: Cohomology of arithmetic groups by Andy Putman (Notre Dame) Title: Buildings, duality, and the high-dimensional cohomology of arithmetic groups Abstract: I will discuss topological results about the cohomology of arithmetic groups, focusing for simplicity on the group SL(n,Z). Topics include the Borel-Serre bordification, Bieri-Eckmann duality, the structure of the Steinberg module, and the high-dimensional cohomology of these groups. » Read more

  • 10 May 2017, 11:30-12:30

    Masterclass Lecture III by Harald Grobner

    Lecture in Masterclass: Cohomology of arithmetic groups by Harald Grobner (Universität Wien) Title: Cohomological automorphic forms: A survey based on examples. Abstract: In this lecture series we will study the cohomology of arithmetic groups through the theory of automorphic forms. Firstly conjectured by A. Borel and G. Harder, the cohomology H^q(Γ, E) of an arithmetic (congruence) subgroup Γ of a connected reductive group G is isomorphic to the relative Lie algebra cohomology of a space of automorphic forms on G. It is really due to epoch-making work of J. Franke that this identication of group-cohomology and automorphic cohomology is now known in full generality. This connection of automorphic forms with the cohomology of arithmetic groups is the deep source of a highly interesting mélange of ideas, approaches and moreover possible applications. It turns out that cohomological automorphic forms i.e., automorphic forms contributing to the cohomology H^q(Γ, E) of some arithmetic group Γ as above play the key role in an extremely rich area of mathematical problems: To mention one of their highlights, the analysis of ζ-functions and their generalizations. This lecture series will (try to) put a spotlight on (i) the problems connected with the very study of H^q(Γ, E) by cohomological automorphic forms, as well as (ii) on some of the far-reaching applications, mentioned above. As the title suggests, we will do this based on a selection of interesting examples, while we try to avoid the huge backlock of the general theory. » Read more

  • 11 May 2017, 10:00-11:00

    Masterclass Lecture IV by Andy Putman

    Lecture in Masterclass: Cohomology of arithmetic groups by Andy Putman (Notre Dame) Title: Buildings, duality, and the high-dimensional cohomology of arithmetic groups Abstract: I will discuss topological results about the cohomology of arithmetic groups, focusing for simplicity on the group SL(n,Z). Topics include the Borel-Serre bordification, Bieri-Eckmann duality, the structure of the Steinberg module, and the high-dimensional cohomology of these groups. » Read more

  • 11 May 2017, 11:30-12:30

    Masterclass Lecture IV by Harald Grobner

    Lecture in Masterclass: Cohomology of arithmetic groups by Harald Grobner (Universität Wien) Title: Cohomological automorphic forms: A survey based on examples. Abstract: In this lecture series we will study the cohomology of arithmetic groups through the theory of automorphic forms. Firstly conjectured by A. Borel and G. Harder, the cohomology H^q(Γ, E) of an arithmetic (congruence) subgroup Γ of a connected reductive group G is isomorphic to the relative Lie algebra cohomology of a space of automorphic forms on G. It is really due to epoch-making work of J. Franke that this identication of group-cohomology and automorphic cohomology is now known in full generality. This connection of automorphic forms with the cohomology of arithmetic groups is the deep source of a highly interesting mélange of ideas, approaches and moreover possible applications. It turns out that cohomological automorphic forms i.e., automorphic forms contributing to the cohomology H^q(Γ, E) of some arithmetic group Γ as above play the key role in an extremely rich area of mathematical problems: To mention one of their highlights, the analysis of ζ-functions and their generalizations. This lecture series will (try to) put a spotlight on (i) the problems connected with the very study of H^q(Γ, E) by cohomological automorphic forms, as well as (ii) on some of the far-reaching applications, mentioned above. As the title suggests, we will do this based on a selection of interesting examples, while we try to avoid the huge backlock of the general theory. » Read more

  • 11 May 2017, 14:00-15:00

    Masterclass Lecture by Alexander Kupers

    Lecture in Masterclass: Cohomology of arithmetic groups by Harald Grobner (Universität Wien) Title: Computing K_8(Z) Abstract: We explain how to prove a result announced by Dutour, Elbaz-Vincent and Martinet using the techniques discussed in the masterclass. » Read more

  • 15 May 2017, 12:45

    Joint Number theory/Geometry and Analysis seminar

    Speaker: Yiannis N. Petridis (UCL/UCPH). Title: Arithmetic Statistics of modular symbols. » Read more

  • 17 May 2017, 15:15-16:15

    Operator algebra seminar

    Seminar talk given by Rasmus Bentmann (University of Göttingen) » Read more

  • 22 May 2017, 13:30-14:30

    Algebra/Topology Seminar by Simona Settepanella

    Talk by Simona Settepanella (Hokkaido University) Title and Abstract: TBA » Read more

  • 22 May 2017, 15:15-16:15

    Algebra/Topology Seminar by Cristiano Spotti

    Talk by Cristiano Spotti (Aarhus) Title and Abstract: TBA » Read more

  • 24 May 2017, 15:15-16:15

    Operator algebra seminar

    Seminar talk given by Elizabeth Gillaspy (University of Muenster) » Read more

  • 26 June - 30 June 2017

    Stable Homotopy Theory and p-adic Hodge Theory

    Masterclass with Matthew Morrow (Jussieu-Paris) and Thomas Nikolaus (MPI Bonn). » Read more

  • 5 August - 6 August 2017

    Young Women in C*-Algebras

    A mini-workshop in the weekend leading up to the Young Mathematicians in C*-Algebras conference where all women participating in the YMC*A are invited to speak. » Read more

  • 7 August - 11 August 2017

    Young Mathematicians in C*-Algebras 2017

    The conference will feature mini-courses by Kate Juschenko (Northwestern) and Guoliang Yu (Texas A&M) alongside many contributed talks by participants. » Read more

  • 16 October - 20 October 2017

    Rigidity of C*-algebras associated to dynamics

    Masterclass with lectures by Toke Meier Carlsen (Faroe Islands) and Xin Li (Queen Mary University of London). » Read more