{ "id": "1904.11537", "version": "v1", "published": "2019-04-25T18:55:11.000Z", "updated": "2019-04-25T18:55:11.000Z", "title": "A counterexample to Fuglede's conjecture in $(\\mathbb{Z}/p\\mathbb{Z})^4$ for all odd primes", "authors": [ "Sam Mattheus" ], "comment": "This result was found simultaneously and independently with [arXiv:1901.08734]. However, it contained an error which was fixed afterwards (again independently). So although not suitable for publication, we record it here as it gives a more geometrical approach to more or less the same construction", "categories": [ "math.CO", "math.CA" ], "abstract": "In this short note we construct a spectral, non-tiling set of size $2p$ in $(\\mathbb{Z}/p\\mathbb{Z})^4$, $p$ odd prime. This example complements a previous counterexample in [arXiv:1509.01090], which existed only for $p \\equiv 3 \\pmod{4}$. On the contrary we show that the conjecture does hold in $(\\mathbb{Z}/2\\mathbb{Z})^4$.", "revisions": [ { "version": "v1", "updated": "2019-04-25T18:55:11.000Z" } ], "analyses": { "keywords": [ "odd prime", "fugledes conjecture", "counterexample", "short note" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }