Search for dissertations about: "David Rydh"

Showing result 1 - 5 of 8 swedish dissertations containing the words David Rydh.

  2. 1. Families of cycles and the Chow scheme

    Author : David Rydh; Dan Laksov; Martin Olsson; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Families of cycles; Chow scheme; Hilbert scheme; zero-cycles; divided powers; symmetric tensors; symmetric product; Weil restriction; norm functor; Algebra and geometry; Algebra och geometri;

    Abstract : The objects studied in this thesis are families of cycles on schemes. A space — the Chow variety — parameterizing effective equidimensional cycles was constructed by Chow and van der Waerden in the first half of the twentieth century. Even though cycles are simple objects, the Chow variety is a rather intractable object. READ MORE

  4. 2. Building Data for Stacky Covers and the Étale Cohomology Ring of an Arithmetic Curve : Du som saknar dator/datorvana kan kontakta [email protected] för information

    Author : Eric Ahlqvist; David Professor; Niels Borne; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Étale Cohomology; Number Field; Cup Product; Stacky Covers; Building Data; Ramified Covers; Mathematics; Matematik;

    Abstract : This thesis consists of two papers with somewhat different flavours. In Paper I we compute the étale cohomology ring H^*(X,Z/nZ) for X the ring of integers of a number field K. As an application, we give a non-vanishing formula for an invariant defined by Minhyong Kim. READ MORE

  5. 3. Stacky Modifications and Operations in the Étale Cohomology of Number Fields

    Author : Eric Ahlqvist; David Rydh; Alexander Schmidt; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; stacks; ramified covers; étale cohomology; cup product; Massey product; Galois cohomology; building data; 2-cocycles; Matematik; Mathematics;

    Abstract : This thesis consists of 4 papers. In Paper A we define stacky building data for stacky covers in the spirit of Pardini and give an equivalence of (2,1)- categories between the category of stacky covers and the category of stacky building data. READ MORE

  6. 4. Computations in the Grothendieck Group of Stacks

    Author : Daniel Bergh; Torsten Ekedahl; David Rydh; Jochen Heinloth; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Mathematics; matematik;

    Abstract : Given an algebraic group, one may consider the class of its classifying stackin the Grothendieck group of stacks. This is an invariant studied byEkedahl. For certain connected groups, called the special groups bySerre and Grothendieck, the invariant simply gives the inverse of the class ofthe group itself. READ MORE

  7. 5. Destackification and Motivic Classes of Stacks

    Author : Daniel Bergh; David Rydh; Dan Edidin; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Algebraic geometry; Algebraic stacks; Destackification; Grothendieck ring; Motive; Torus; Classifying stack; Mathematics; matematik;

    Abstract : This thesis consists of three articles treating topics in the theory of algebraic stacks. The first two papers deal with motivic invariants. In the first, we show that the class of the classifying stack BPGLn is the inverse of the class of PGLn in the Grothendieck ring of stacks for n ≤ 3. READ MORE