English

Geometry of Integral Binary Hermitian Forms

Number Theory 2011-11-10 v2 Geometric Topology

Abstract

We generalize Conway's approach to integral binary quadratic forms on Q to study integral binary hermitian forms on quadratic imaginary extensions of Q. In Conway's case, an indefinite form that doesn't represent 0 determines a line ("river") in the spine T associated with SL(2,Z) in the hyperbolic plane. In our generalization, such a form determines a plane ("ocean") in Mendoza's spine associated with the corresponding Bianchi group SL(2,A) in hyperbolic 3-space.

Keywords

Cite

@article{arxiv.1104.1474,
  title  = {Geometry of Integral Binary Hermitian Forms},
  author = {Mladen Bestvina and Gordan Savin},
  journal= {arXiv preprint arXiv:1104.1474},
  year   = {2011}
}
R2 v1 2026-06-21T17:51:08.352Z