28 Oct 2020
    
    
      Seminar, Lecture, Talk
    
    
      MATH - Seminar on Pure Mathematics - Counting sheaves on Calabi-Yau 4-folds
    
    
      
  
    
      
        
          We define a localised Euler class for isotropic sections, and isotropic cones, in SO(N) bundles. We use this to give an algebraic definition of Borisov-Joyce's sheaf counting invariants on Calabi-Yau 4-folds.