524 research outputs found

    On certain classes of p-Valent functions by using complex-order and differential subordination.

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    The aim of the present paper is to study the p-valent analytic functions in the unit disk and satisfy the differential subordinations z(Ip)r, ?(f(z))(j+1)/(p - j)(?p(r, ?)f(z))(j) < (a + (aB + (A- B)ß)z)/a(1 + Bz), where ?p(r, ?) is an operator defined by Salagean and ßis a complex number. Further we define a new related integral operator and also study the Fekete-Szego problem by proving some interesting properties

    Certain subclasses of multivalent functions defined by new multiplier transformations

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    In the present paper the new multiplier transformations \mathrm{{\mathcal{J}% }}_{p}^{\delta }(\lambda ,\mu ,l) (\delta ,l\geq 0,\;\lambda \geq \mu \geq 0;\;p\in \mathrm{% }%\mathbb{N} )} of multivalent functions is defined. Making use of the operator Jpδ(λ,μ,l),\mathrm{% {\mathcal{J}}}_{p}^{\delta }(\lambda ,\mu ,l), two new subclasses Pλ,μ,lδ(A,B;σ,p)\mathcal{% P}_{\lambda ,\mu ,l}^{\delta }(A,B;\sigma ,p) and P~λ,μ,lδ(A,B;σ,p)\widetilde{\mathcal{P}}% _{\lambda ,\mu ,l}^{\delta }(A,B;\sigma ,p)\textbf{\ }of multivalent analytic functions are introduced and investigated in the open unit disk. Some interesting relations and characteristics such as inclusion relationships, neighborhoods, partial sums, some applications of fractional calculus and quasi-convolution properties of functions belonging to each of these subclasses Pλ,μ,lδ(A,B;σ,p)\mathcal{P}_{\lambda ,\mu ,l}^{\delta }(A,B;\sigma ,p) and P~λ,μ,lδ(A,B;σ,p)\widetilde{\mathcal{P}}_{\lambda ,\mu ,l}^{\delta }(A,B;\sigma ,p) are investigated. Relevant connections of the definitions and results presented in this paper with those obtained in several earlier works on the subject are also pointed out

    Bounds for the Second Hankel Determinant of Certain Univalent Functions

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    The estimates for the second Hankel determinant a_2a_4-a_3^2 of analytic function f(z)=z+a_2 z^2+a_3 z^3+...b for which either zf'(z)/f(z) or 1+zf"(z)/f'(z) is subordinate to certain analytic function are investigated. The estimates for the Hankel determinant for two other classes are also obtained. In particular, the estimates for the Hankel determinant of strongly starlike, parabolic starlike, lemniscate starlike functions are obtained

    Subclasses of meromorphically multivalent functions defined by a differential operator

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    In this paper we introduce and study two new subclasses \Sigma_{\lambda\mu mp}(\alpha,\beta)and and \Sigma^{+}_{\lambda\mu mp}(\alpha,\beta)ofmeromorphicallymultivalentfunctionswhicharedefinedbymeansofanewdifferentialoperator.Someresultsconnectedtosubordinationproperties,coefficientestimates,convolutionproperties,integralrepresentation,distortiontheoremsareobtained.Wealsoextendthefamiliarconceptof of meromorphically multivalent functions which are defined by means of a new differential operator. Some results connected to subordination properties, coefficient estimates, convolution properties, integral representation, distortion theorems are obtained. We also extend the familiar concept of % (n,\delta)-$neighborhoods of analytic functions to these subclasses of meromorphically multivalent functions

    Subordination And Convolution Of Multivalent Functions And Starlikeness Of Integral Transforms

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    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
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