Sharp estimates for Hübner’s upper bound function with applications

Autor: Song-liang Qiu, Liang-Yu Ren
Rok vydání: 2010
Předmět:
Zdroj: Applied Mathematics-A Journal of Chinese Universities. 25:227-235
ISSN: 1993-0445
1005-1031
DOI: 10.1007/s11766-010-2203-3
Popis: New better estimates, which are given in terms of elementary functions, for the function r 7→ (2/�)(1 − r 2 )K(r)K ' (r) + log r appearing in Hubner's sharp upper bound for the Hersch-Pfluger distortion function are obtained. With these estimates, some known bounds for the Hersch-Pfluger distortion function in quasiconformal theory are improved, thus improving the explicit quasiconformal Schwarz lemma and some known estimates for the solutions to the Ramanujan modular equations.
Databáze: OpenAIRE