{ "id": "2312.12043", "version": "v1", "published": "2023-12-19T10:55:54.000Z", "updated": "2023-12-19T10:55:54.000Z", "title": "Rational approximations to values of $E$-functions", "authors": [ "Stéphane Fischler", "Tanguy Rivoal" ], "comment": "32 pages", "categories": [ "math.NT" ], "abstract": "We solve a long standing problem in the theory of Siegel's $E$-functions, initiated by Lang for Bessel's function $J_0$ in the 60's and considered in full generality by G. Chudnovsky in the 80's: we prove that irrational values taken at rational points by $E$-functions with rational Taylor coefficients have irrationality exponent equal to 2. This result had been obtained before by Zudilin under stronger assumptions on algebraic independence of $E$-functions, satisfied by $J_0$ but not by all hypergeometric $E$-functions for instance.", "revisions": [ { "version": "v1", "updated": "2023-12-19T10:55:54.000Z" } ], "analyses": { "subjects": [ "11J82", "11J91" ], "keywords": [ "rational approximations", "irrational values taken", "rational taylor coefficients", "irrationality exponent equal", "rational points" ], "note": { "typesetting": "TeX", "pages": 32, "language": "en", "license": "arXiv", "status": "editable" } } }