35 research outputs found
Sufficient conditions of starlikeness and convexity for functions of complex order
Let A be the class of normalised and analytic functions defined in the unit disc {:||1}.Uzz
In this paper we study the expression
2()1,,()()zfzzzUbfzbfz
for some (0) and (\{0}bb as a criteria for starlikeness and convexity at analytic functions of complex order
Differential Subordination And Coefficients Problems Of Certain Analytic Functions
Let A be the class of normalized analytic functions f on the unit disk D, in
the form f(z) = z+
P1n
=2 anzn: A function f in A is univalent if it is a one-to-one
mapping. This thesis discussed ¯ve research problems.
Lambangkan A sebagai kelas fungsi analisis ternormal pada cakera unit D
berbentuk f(z) = z +
P1n
=2 anzn: Fungsi f dalam A adalah univalen jika fungsi
tersebut ialah pemetaan satu ke satu. Tesis ini mengkaji lima masalah penye-
lidikan
Subordination And Convolution Of Multivalent Functions And Starlikeness Of Integral Transforms
This thesis deals with analytic functions as well as multivalent functions de-
�ned on the unit disk U. In most cases, these functions are assumed to be normalized,
either of the form
f(z) = z +
1X
k=2
akzk;
or
f(z) = zp +
1X
k=1
ak+pzk+p;
p a �xed positive integer. Let A be the class of functions f with the �rst normalization,
while Ap consists of functions f with the latter normalization. Five
research problems are discussed in this work.
First, let f(q) denote the q-th derivative of a function f 2 Ap. Using the theory
of di�erential subordination, su�cient conditions are obtained for the following
di�erential chain to hold:
f(q)(z)
�(p; q)z
Analytic and Harmonic Univalent Functions
Studies on analytic univalent functions became the focus of
intense researchwith theBieberbachconjectureposed in 1916
concerning the size of the moduli of the Taylor coefficients
of these functions. In efforts towards its resolution, the
conjecture inspired the development of several ingeniously
different mathematical techniques with powerful influence.
These techniques include Lowner’s parametric representation
method, the area method,Grunsky inequalities, and methods
of variations.Despite the fact that the conjecture was affirmatively
settled by de Branges in 1985, complex function theory
continued to remain a highly active relevant area of research
Differential Subordination And Superordination For Analytic And Meromorphic Functions Defined By Linear Operators [QA331. N219 2007 f rb].
Suatu fungsi f yang tertakrif pada cakera unit terbuka U dalam satah kompleks C disebut univalen jika fungsi tersebut memetakan titik berlainan dalam U ke titik berlainan dalam C.
A function f defined on the open unit disk U of the complex plane C is univalent if it maps different points of U to different points of C
Inclusion Properties Of Linear Operators And Analytic Functions
This thesis studies the class A of normalized analytic functions in the open unit
disk U of the complex plane. The class of meromorphic functions in the punctured
unit disk which does not include the origin is also studied. This thesis investigates
six research problems. First, the classical subclasses of starlike, convex, close-toconvex
and quasi-convex functions are extended by introducing new subclasses
of analytic and meromorphic functions. The closure properties of these newly
de ned classes are investigated and it is shown that these classes are closed under
convolution with prestarlike functions and the Bernardi-Libera-Livingston integral
operator.
The univalence of functions f(z) = z +
P1n=2 anzn 2 A is investigated by
requiring the Schwarzian derivative S(f; z) and the second coe cient a2 of f to
satisfy certain inequalities. New criterion for analytic functions to be strongly -
Bazilevi c of nonnegative order is established in terms of the Schwarzian derivatives
and the second coe cients. Also, similar conditions on the second coe cient
of f and its Schwarzian derivative S(f; z) are obtained that would ensure the
function f belongs to particular subclasses of S. For an analytic function f(z) =
z+
P1n
=2 anzn 2 A satisfying the inequality
P1n
=2 n(