Arama Sonuçları

Listeleniyor 1 - 5 / 5
  • Yayın
    Close-to-convex functions defined by fractional operator
    (2013) Aydoğan, Seher Melike; Kahramaner, Yasemin; Polatoğlu, Yaşar
    Let S denote the class of functions f(z) = z + a2z2+... analytic and univalent in the open unit disc D = {z ∈ C||z|<1}. Consider the subclass and S* of S, which are the classes ofconvex and starlike functions, respectively. In 1952, W. Kaplan introduced a class of analyticfunctions f(z), called close-to-convex functions, for which there existsφ(Z) ∈ C, depending on f(z) with Re( f′(z)/φ′(z) ) > 0 in , and prove that every close-to-convex function is univalent. The normalized class of close-to-convex functions denoted by K. These classesare related by the proper inclusions C ⊂ S* ⊂ K ⊂ S. In this paper, we generalize the close-to-convex functions and denote K(λ) the class of such functions. Various properties of this class of functions is alos studied.
  • Yayın
    Harmonic mappings related to Janowski convex functions of complex order b
    (2013) Aydoğan, Seher Melike; Polatoğlu, Yaşar; Kahramaner, Yasemin
    Let SH be the class of all sense-preserving harmonic mappings in the open unit disc D = {z ∈ ℂ||z| < 1}. In the present paper the authors investigate the properties of the class of harmonic mappings which is based on the generalized of R. J. Libera Theorem [7].
  • Yayın
    Quasiconformal harmonic mappings related to Janowski alpha-spirallike functions
    (Amer Inst Physics, 2014) Aydoğan, Seher Melike; Polatoğlu, Yaşar
    Let f = h(z) + g(z) be a univalent sense-preserving harmonic mapping of the open unit disc D = {z/vertical bar z vertical bar < 1}. If f satisfies the condition vertical bar omega(z)vertical bar = vertical bar g'(z)/h'(z)vertical bar < k, 0 < k < 1 the f is called k-quasiconformal harmonic mapping in D. In the present paper we will give some properties of the class of k-quasiconformal mappings related to Janowski alpha-spirallike functions.
  • Yayın
    Notes on starlike log-harmonic functions of order α
    (2013) Aydoğan, Seher Melike; Duman, Emel Yavuz; Owa, Shigeyoshi
    For log-harmonic functions f(z) = zh(z)g(z) in the open unit disk U, two subclasses H*LH(α) and G*LH(α) of S*LH(α) consisting of all starlike log-harmonic functions of order α (0 ≤ α < 1) are considered. The object of the present paper is to discuss some coefficient inequalities for h(z) and g(z).Mathematics Subject Classification: Primary 30C55, Secondary 30C45.
  • Yayın
    Bounded harmonic mappings related to starlike functions
    (Amer Inst Physics, 2014-12-17) Varol, Dürdane; Aydoğan, Seher Melike; Polatoğlu, Yaşar
    Let f = h(z) + <(g(z))over bar> be a sense-preserving harmonic mapping in the open unit disc D = {z vertical bar vertical bar z vertical bar < 1}. If f satisfies the condition vertical bar 1/b(1) g'(z)/h' (z) - M vertical bar < M, M > 1/2, then f is called bounded harmonic mapping. The main purpose of this paper is to give some properties of the class of bounded harmonic mapping.