Open AccessSome general families of q-starlike functions associated with the Janowski functions
Author(s) -
H. M. Srivástava,
Muhammad Tahir,
Bilal Khan,
Qazi Ahmad Zahoor,
Nazar Khan
Publication year - 2019
Publication title -
filomat
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.449
H-Index - 34
eISSN - 2406-0933
pISSN - 0354-5180
DOI - 10.2298/fil1909613s
Subject(s) - mathematics , unit disk , argument (complex analysis) , section (typography) , conic section , pure mathematics , discrete mathematics , algebra over a field , computer science , geometry , biochemistry , chemistry , operating system
By making use of the concept of basic (or q-) calculus, various families of q-extensions of starlike functions, which are associated with the Janowski functions in the open unit disk U, were introduced and studied from many different viewpoints and perspectives. In this paper, we first investigate the relationship between various known families of q-starlike functions which are associated with the Janowski functions. We then introduce and study a new subclass of q-starlike functions which involves the Janowski functions and is related with the conic domain. We also derive several properties of such families of q-starlike functions with negative coefficients including (for example) sufficient conditions, inclusion results and distortion theorems. In the last section on conclusion, we choose to point out the fact that the results for the q-analogues, which we consider in this article for 0 < q < 1, can easily (and possibly trivially) be translated into the corresponding results for the (p; q)-analogues (with 0 < q < p ?? 1) by applying some obvious parametric and argument variations, the additional parameter p being redundant.