The image of the Borel-Serre bordification in algebraic K-theory
type: Dataset
description: We give a method for constructing explicit non-trivial elements in the third K-group (modulo torsion) of an imaginary quadratic number field. These arise from the relative homology of the map attaching the Borel-Serre boundary to the orbit space of the SL_2 group over the ring of imaginary quadratic integers on its symmetric space - hyperbolic three-space. We provide an algorithm which produces a chain of matrix quadruples specifying our element of K_3 of the field, modulo torsion. We carry out the algorithm for the Eisenteinian integers as well as for the imaginary quadratic integers of discriminant -7.
issued: 2026-05-05T16:00:30.731612
language: en
modified: 2026-05-05T16:00:30.731616
contact point: Organization
  fn: CCSD
keyword: infoeu-reposemanticspreprint
keyword: mathmath-ktmathematics-mathk-theory-and-homology-mathkt
keyword: preprints-working-papers-
landing page: https://hal.science/hal-00975454

The image of the Borel-Serre bordification in algebraic K-theory
type: Distribution
format: HTML
issued: 2026-05-05T16:00:30.733849
modified: 2026-05-05T16:00:30.726795
access URL: https://hal.science/hal-00975454

test_moissonnage_selune
type: Agent