{ "id": "2209.07107", "version": "v1", "published": "2022-09-15T07:36:39.000Z", "updated": "2022-09-15T07:36:39.000Z", "title": "Quadratic Pairs on Azumaya Algebras over a Scheme", "authors": [ "Philippe Gille", "Erhard Neher", "Cameron Roy Ruether" ], "categories": [ "math.AG", "math.RA" ], "abstract": "We investigate quadratic pairs for Azumaya algebras with involutions over a base scheme S as defined by Calm{\\`e}s and Fasel, generalizing the case of quadratic pairs on central simple algebras over a field (Knus, Merkurjev, Rost, Tignol). We describe a cohomological obstruction for an Azumaya algebra over S with orthogonal involution to admit a quadratic pair. When S is affine this obstruction vanishes, however it is non-trivial in general. In particular, we construct explicit examples with non-trivial obstructions.", "revisions": [ { "version": "v1", "updated": "2022-09-15T07:36:39.000Z" } ], "analyses": { "keywords": [ "quadratic pair", "azumaya algebra", "central simple algebras", "construct explicit examples", "orthogonal involution" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }