{ "id": "2303.11468", "version": "v1", "published": "2023-03-20T21:52:22.000Z", "updated": "2023-03-20T21:52:22.000Z", "title": "Special functions and dual special functions in Drinfeld modules of arbitrary rank", "authors": [ "Giacomo Hermes Ferraro" ], "comment": "15 pages", "categories": [ "math.NT" ], "abstract": "In a previous paper, the author showed in the context of Drinfeld-Hayes modules that the product between a special function and a Pellarin zeta function is rational, and that the latter can be interpreted as a dual special function. Both results are generalized in this paper. We use a very simple functorial point of view to interpret special functions and dual special functions in Drinfeld modules of arbitrary rank, allowing us to define a universal special function $\\omega_\\phi$ and a universal dual special function $\\zeta_\\phi$. In analogy to the Drinfeld-Hayes case, we prove that the latter can be expressed as an Eisenstein-like series over the period lattice, and that the scalar product $\\omega_\\phi\\cdot\\zeta_\\phi$, an element of $\\mathbb{C}_\\infty\\hat\\otimes\\Omega$, is rational. We also describe the module of special functions in the generality of Anderson modules, as already done by Gazda and Maurischat, and answer a question posed in that same paper about the invertibility of special functions in the context of Drinfeld-Hayes modules.", "revisions": [ { "version": "v1", "updated": "2023-03-20T21:52:22.000Z" } ], "analyses": { "subjects": [ "11G09" ], "keywords": [ "drinfeld modules", "arbitrary rank", "drinfeld-hayes modules", "universal dual special function", "pellarin zeta function" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }