English

Bilinear forms on Grothendieck groups of triangulated categories

Representation Theory 2017-09-13 v1

Abstract

We extend the theory of bilinear forms on the Green ring of a finite group developed by Benson and Parker to the context of the Grothendieck group of a triangulated category with Auslander-Reiten triangles, taking only relations given by direct sum decompositions. We examine the non-degeneracy of the bilinear form given by dimensions of homomorphisms, and show that the form may be modified to give a Hermitian form for which the standard basis given by indecomposable objects has a dual basis given by Auslander-Reiten triangles. An application is given to the homotopy category of perfect complexes over a symmetric algebra, with a consequence analogous to a result of Erdmann and Kerner.

Keywords

Cite

@article{arxiv.1709.03889,
  title  = {Bilinear forms on Grothendieck groups of triangulated categories},
  author = {Peter Webb},
  journal= {arXiv preprint arXiv:1709.03889},
  year   = {2017}
}

Comments

arXiv admin note: substantial text overlap with arXiv:1301.4701