{ "id": "math/0203264", "version": "v4", "published": "2002-03-26T00:20:17.000Z", "updated": "2004-08-23T22:17:01.000Z", "title": "On reducing the Heun equation to the hypergeometric equation", "authors": [ "Robert S. Maier" ], "comment": "36 pages, a few additional misprints corrected", "journal": "J. Differential Equations 213 (2005) 171-203", "doi": "10.1016/j.jde.2004.07.020", "categories": [ "math.CA", "math-ph", "math.MP" ], "abstract": "The reductions of the Heun equation to the hypergeometric equation by polynomial transformations of its independent variable are enumerated and classified. Heun-to-hypergeometric reductions are similar to classical hypergeometric identities, but the conditions for the existence of a reduction involve features of the Heun equation that the hypergeometric equation does not possess; namely, its cross-ratio and accessory parameters. The reductions include quadratic and cubic transformations, which may be performed only if the singular points of the Heun equation form a harmonic or an equianharmonic quadruple, respectively; and several higher-degree transformations. This result corrects and extends a theorem in a previous paper, which found only the quadratic transformations. [See K. Kuiken, \"Heun's equation and the hypergeometric equation\", SIAM Journal on Mathematical Analysis 10:3 (1979), 655-657.]", "revisions": [ { "version": "v4", "updated": "2004-08-23T22:17:01.000Z" } ], "analyses": { "subjects": [ "33E30", "34M35", "33C05" ], "keywords": [ "hypergeometric equation", "heun equation form", "polynomial transformations", "accessory parameters", "heun-to-hypergeometric reductions" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 36, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2002math......3264M" } } }