Results 1 to 10 of about 537,864 (334)
On Becker's univalence criterion [PDF]
We study locally univalent functions $f$ analytic in the unit disc $\mathbb{D}$ of the complex plane such that $|{f"(z)/f'(z)}|(1-|z|^2)\leq 1+C(1-|z|)$ holds for all $z\in\mathbb{D}$, for some ...
Huusko, Juha-Matti, Vesikko, Toni
core +3 more sources
Vector Fields on the Space of Functions Univalent Inside the Unit Disk via Faber Polynomials [PDF]
We obtain the Kirillov vector fields on the set of functions $f$ univalent inside the unit disk, in terms of the Faber polynomials of $1/f(1/z)$.
Airault, Helene
core +5 more sources
Univalency of Certain Transform of Univalent Functions
We consider univalency problem in the unit disc $$\mathbb{D}$$ of the function \[g(z)=\frac{(z/f(z))-1}{-a_{2}}, \] where $$f$$ belongs to some classes of univalent functions in $$\mathbb{D}$$ and $$a_{2}=\frac{f''(0)}{2}\neq 0$$.
Obradović, Milutin, Tuneski, Nikola
openaire +3 more sources
On the Univalence of Poly-analytic Functions [PDF]
A continuous complex-valued function $F$ in a domain $D\subseteq\mathbf{C}$ is Poly-analytic of order $ $ if it satisfies $\partial^ _{\overline{z}}F=0.$ One can show that $F$ has the form $F(z)={\displaystyle\sum\limits_{0}^{n-1}}\overline{z}^{k}A_{k}(z)$, where each $A_k$ is an analytic function$.$ In this paper, we prove the existence of a Landau ...
Layan El Hajj, Zayid Abdulhadi
openaire +3 more sources
NEIGHBOURHOODS OF UNIVALENT FUNCTIONS [PDF]
AbstractThe main result shows that a small perturbation of a univalent function is again a univalent function, hence a univalent function has a neighbourhood consisting entirely of univalent functions. For the particular choice of a linear function in the hypothesis of the main theorem, we obtain a corollary which is equivalent to the classical Noshiro–
Nicolae R. Pascu, Mihai N. Pascu
openaire +3 more sources
Product of univalent functions [PDF]
Abstract Let S denote the class of functions f analytic and univalent in the unit disk | z | 1 normalized such that f ( 0 ) = 0 = f ′ ( 0 ) − 1 . In this article the authors discuss the radius of univalence of F ( z ) = g ( z ) h ( z ) / z when g and h belong ...
Obradović, Milutin+1 more
openaire +1 more source
Univalent harmonic functions [PDF]
Several families of complex-valued, univalent, harmonic functions are studied from the point of view of geometric function theory. One class consists of mappings of a simply-connected domain onto an infinite horizontal strip with a normalization at the origin.
Glenn Schober, Walter Hengartner
openaire +2 more sources
A class of univalent functions [PDF]
A sharp coefficient estimate is obtained for a class D ( α ) D(\alpha ) of functions univalent in the open unit disc. The radius of convexity and an arclength result are also determined for the class.
T. R. Caplinger, W. M. Causey
openaire +2 more sources
A first-order differential double subordination with applications [PDF]
Let $q_1$ and $q_2$ belong to a certain class of normalized analytic univalent functions in the open unit disk of the complex plane. Sufficient conditions are obtained for normalized analytic functions $p$ to satisfy the double subordination chain $q_1(z)
Ali+20 more
core +2 more sources
On a class of univalent functions
AbstractLet A be the class of analytic functions in the unit disk D with the normalization f(0)=f′(0)−1=0. Denote by N the class of functions f∈A which satisfy the condition |−z3(zf(z))‴+f′(z)(zf(z))2−1|≤1,z∈D. We show that functions in N are univalent in D but not necessarily starlike.
Obradović, Milutin+1 more
openaire +2 more sources