English

$J$-invariant of hermitian forms over quadratic extensions

Algebraic Geometry 2019-08-14 v7

Abstract

We develop the version of the JJ-invariant for hermitian forms over quadratic extensions in a similar way Alexander Vishik did it for quadratic forms. This discrete invariant contains informations about rationality of algebraic cycles on the maximal unitary grassmannian associated with a hermitan form over a quadratic extension. The computation of the canonical 22-dimension of this grassmannian in terms of the JJ-invariant is provided, as well as a complete motivic decomposition.

Keywords

Cite

@article{arxiv.1602.04079,
  title  = {$J$-invariant of hermitian forms over quadratic extensions},
  author = {Raphaël Fino},
  journal= {arXiv preprint arXiv:1602.04079},
  year   = {2019}
}