نتایج جستجو برای: starlike and convex function

تعداد نتایج: 16948100  

2007
Vanessa Bertoni Dimitar K. Dimitrov V. Bertoni D. K. Dimitrov

Alexander [1] was the first to introduce certain subclasses of univalent functions examining the geometric properties of the image f(D) of D under f . The convex functions are those that map D onto a convex set. A function w = f(z) is said to be starlike if, together with any of its points w, the image f(D) contains the entire segment {tw : 0 ≤ t ≤ 1}. Thus we introduce the denotations S = {f ∈...

Journal: :Int. J. Math. Mathematical Sciences 2008
Akshaya Kumar Mishra Priyabrat Gochhayat

Also let S, S∗ β , CV β , and K denote, respectively, the subclasses of A0 consisting of functions which are univalent, starlike of order β, convex of order β cf. 1 , and close-to-convex cf. 2 in U. In particular, S∗ 0 S∗ and CV 0 CV are the familiar classes of starlike and convex functions in U cf. 2 . Given f and g inA, the function f is said to be subordinate to g in U if there exits a funct...

Journal: :Int. J. Math. Mathematical Sciences 2010
Ma'moun Harayzeh Al-Abbadi Maslina Darus

which are analytic in the open unit disc U {z ∈ C : |z| < 1} on the complex plane C. Let S, S∗ α , C α 0 ≤ α < 1 denote the subclasses of A consisting of functions that are univalent, starlike of order α, and convex of order α in U, respectively. In particular, the classes S∗ 0 S∗ and C 0 C are the familiar classes of starlike and convex functions inU, respectively. A function f ∈ C α if Re 1 z...

2009
S. M. Khairnar

AbstractIn this paper we introduce the subclass K(μ, γ, η, α, β) of β-uniformly convex and β-uniformly starlike functions which are analytic and multivalent with negative coefficients defined by using fractional calculus operators. Characterization property exhibited by the functions in the class and the results of modified Hadamard product are discussed. Connections with the popular subclasses...

Journal: :Int. J. Math. Mathematical Sciences 2008
Oh Sang Kwon Nak Eun Cho

The purpose of the present paper is to give some characterizations for a Gaussian hypergeometric function to be in various subclasses of starlike and convex functions. We also consider an integral operator related to the hypergeometric function.

2014
A. O. MOSTAFA

In this paper we introduce new subclasses of p-valent starlike, pvalent convex, p-valent close-to-convex and p-valent quasi-convex meromorphic functions and investigate some inclusion properties of these subclasses and investigate various inclusion properties and integral-preserving properties for the p-valent meromorphic function classes.

Journal: :Applied Mathematics and Computation 2010
R. Chandrashekar Rosihan M. Ali See Keong Lee V. Ravichandran

It is well-known that the classes of starlike, convex and close-to-convex univalent functions are closed under convolution with convex functions. In this paper, closure properties under convolution of general classes of meromorphic p-valent functions that are either starlike, convex or close-to-convex with respect to n-ply symmetric, conjugate and symmetric conjugate points are investigated. 20...

2009
A. O. MOSTAFA

The objective of the present paper is to give some characterizations for a (Gaussian) hypergeometric function to be in various subclasses of starlike and convex functions. We also consider an integral operator related to the hypergeometric function.

2008
Toshio Hayami Shigeyoshi Owa

Some subclasses of analytic functions f(z) in the open unit disk U are introduced. In the present paper, Some interesting sufficient conditions, including coefficient inequalities related close-to-convex functions f(z) of order α with respect to a fixed starlike function g(z) and strongly starlike functions f(z) of order μ in U, are discussed. Several special cases and consequences of these coe...

Journal: :Int. J. Math. Mathematical Sciences 2011
Toshio Hayami Shigeyoshi Owa

For p-valently Janowski starlike and convex functions defined by applying subordination for the generalized Janowski function, the sharp upper bounds of a functional |a p2 − μa 2 p1 | related to the Fekete-Szegö problem are given.

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