{ "id": "1601.01501", "version": "v1", "published": "2016-01-07T12:01:11.000Z", "updated": "2016-01-07T12:01:11.000Z", "title": "Cumulants of Jack symmetric functions and $b$-conjecture", "authors": [ "Maciej Dołęga", "Valentin Féray" ], "comment": "26 pages, 2 figures, comments are welcome", "categories": [ "math.CO" ], "abstract": "Goulden and Jackson (1996) introduced, using Jack symmetric functions, some multivariate generating series $\\psi(x, y, z; t, 1+\\beta)$ that might be interpreted as a continuous deformation of generating series of rooted hypermaps. They made the following conjecture: the coefficients of $\\psi(x, y, z; t, 1+\\beta)$ in the power-sum basis are polynomials in $\\beta$ with nonnegative integer coefficients (by construction, these coefficients are rational functions in $\\beta$). We prove partially this conjecture, nowadays called $b$-conjecture, by showing that coefficients of $\\psi(x, y, z; t, 1+ \\beta)$ are polynomials in $\\beta$ with rational coefficients. A key step of the proof is a strong factorization property of Jack polynomials when $\\alpha$ tends to $0$, that may be of independent interest.", "revisions": [ { "version": "v1", "updated": "2016-01-07T12:01:11.000Z" } ], "analyses": { "subjects": [ "05E05" ], "keywords": [ "jack symmetric functions", "conjecture", "strong factorization property", "multivariate generating series", "independent interest" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160101501D" } } }