{ "id": "2203.07870", "version": "v1", "published": "2022-03-07T17:39:19.000Z", "updated": "2022-03-07T17:39:19.000Z", "title": "Fermat's Last Theorem over ${\\mathbb Q}(\\sqrt{5})$ and ${\\mathbb Q}(\\sqrt{17})$", "authors": [ "Imin Chen", "Aisosa Efemwonkieke", "David Sun" ], "categories": [ "math.NT" ], "abstract": "We prove Fermat's Last Theorem over ${\\mathbb Q}(\\sqrt{5})$ and ${\\mathbb Q}(\\sqrt{17})$ for prime exponents $p \\ge 5$ in certain congruence classes modulo $48$ by using a combination of the modular method and Brauer-Manin obstructions explicitly given by quadratic reciprocity constraints. The reciprocity constraint used to treat the case of ${\\mathbb Q}(\\sqrt{5})$ is a generalization to a real quadratic base field of the one used by Chen-Siksek. For the case of ${\\mathbb Q}(\\sqrt{17})$, this is insufficient, and we generalize a reciprocity constraint of Bennett-Chen-Dahmen-Yazdani using Hilbert symbols from the rational field to certain real quadratic fields.", "revisions": [ { "version": "v1", "updated": "2022-03-07T17:39:19.000Z" } ], "analyses": { "subjects": [ "11D41" ], "keywords": [ "real quadratic base field", "congruence classes modulo", "real quadratic fields", "quadratic reciprocity constraints", "modular method" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }