{ "id": "2201.12780", "version": "v1", "published": "2022-01-30T10:28:03.000Z", "updated": "2022-01-30T10:28:03.000Z", "title": "Period -Index problem for hyperelliptic curves", "authors": [ "J. N. Iyer", "R. Parimala" ], "categories": [ "math.AG", "math.NT" ], "abstract": "Let $C$ be a smooth projective curve of genus 2 over a number field $k$ with a rational point. We prove that the index and exponent coincide for elements in the 2-torsion of $\\Sha(Br(C))$. In the appendix, an isomorphism of the moduli space of rank 2 stable vector bundles with odd determinant on a smooth projective hyperelliptic curve $C$ of genus $g$ with a rational point over any field of characteristic not two with the Grassmannian of $(g-1)$-dimensional linear subspaces in the base locus of a certain pencil of quadrics is established, making a result of (\\cite{De-Ra}) rational. We establish a twisted version of this isomorphism and we derive as a consequence a weak Hasse principle for the smooth intersection $X$ of two quadrics in ${\\mathbb P}^5$ over a number field: if $X$ contains a line locally, then $X$ has a $k$-rational point.", "revisions": [ { "version": "v1", "updated": "2022-01-30T10:28:03.000Z" } ], "analyses": { "keywords": [ "index problem", "rational point", "number field", "weak hasse principle", "dimensional linear subspaces" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }