{ "id": "2002.12155", "version": "v1", "published": "2020-02-27T15:04:44.000Z", "updated": "2020-02-27T15:04:44.000Z", "title": "Solutions of $φ(n)=φ(n+k)$ and $σ(n)=σ(n+k)$", "authors": [ "Kevin Ford" ], "comment": "5 pages", "categories": [ "math.NT" ], "abstract": "We show that for some $k\\le 6990$ and all $k$ with $3099044504245996706400|k$, the equation $\\phi(n)=\\phi(n+k)$ has infinitely many solutions $n$, where $\\phi$ is Euler's totient function. We also show that for a positive proportion of all $k$, the equation $\\sigma(n)=\\sigma(n+k)$ has infinitely many solutions $n$. The proofs rely on recent progress on the prime $k$-tuples conjecture by Zhang, Maynard, Tao and PolyMath.", "revisions": [ { "version": "v1", "updated": "2020-02-27T15:04:44.000Z" } ], "analyses": { "subjects": [ "11A25" ], "keywords": [ "eulers totient function", "tuples conjecture", "positive proportion" ], "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable" } } }