Notes on the norm of pre-Schwarzian derivatives of certain analytic functions
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 65, Heft 3, S. 357-363
ISSN: 2065-961X
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In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 65, Heft 3, S. 357-363
ISSN: 2065-961X
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 62, Heft 2, S. 197-204
ISSN: 2065-961X
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 64, Heft 1, S. 63-70
ISSN: 2065-961X
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 66, Heft 4, S. 641-657
ISSN: 2065-961X
In this paper, we establish some (p,q)-Opial type inequalities and generalization of (p,q)-Opial type inequalities.
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 65, Heft 2, S. 199-210
ISSN: 2065-961X
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 62, Heft 2, S. 163-173
ISSN: 2065-961X
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 66, Heft 4, S. 677-690
ISSN: 2065-961X
For any $\mu _{j}\ (\mu _{j}\in \mathbb{C},\left\vert \mu _{j}\right\vert =1,j=1,2)$, we consider the rotations $f_{\mu _{1}}$ and $F_{\mu _{2}}$ of right half-plane harmonic mappings $f,F\in S_{\mathcal{H}}$ which are CHD with the prescribed dilatations $\omega _{f}(z)=\left( a-z\right) /\left(1-az\right) $ for some $a$ $\left( -1<a<1\right) $ and $\omega _{F}(z)=$ $e^{i\theta }z^{n}$ $\left( n\in \mathbb{N},\theta \in \mathbb{R}\right) $, $\omega _{F}(z)=$ $\left( b-z\right) /\left( 1-bz\right) $, $\omega_{F}(z)=\left( b-ze^{i\phi }\right) /\left( 1-bze^{i\phi }\right) $ $(-1<b<1,\phi \in \mathbb{R})$, respectively. It is proved that the convolution $f_{\mu _{1}}\ast F_{\mu _{2}}\in S_{\mathcal{H}}$ and is convex in the direction of $\overline{\mu _{1}\mu _{2}}$ under certain conditions on the parameters involved.
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 63, Heft 4, S. 419-436
ISSN: 2065-961X
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 66, Heft 4, S. 709-722
ISSN: 2065-961X
In this article, we have interested the study of the existence and uniqueness of positive solutions of the first-order nonlinear Hilfer fractional differential equation $$D_{0^{+}}^{\alpha ,\beta }y(t)=f(t,y(t)),\text{ }0<t\leq 1,$$ with the integral boundary condition $$I_{0^{+}}^{1-\gamma }y(0)=\lambda \int_{0}^{1}y(s)ds+d,$$ where $0<\alpha \leq 1,$ $0\leq \beta \leq 1,$ $\lambda \geq 0,$ $d\in \mathbb{R}^{+},$ and $D_{0^{+}}^{\alpha ,\beta }$, $I_{0^{+}}^{1-\gamma }$ are fractional ope\-rators in the Hilfer, Riemann-Liouville concepts, respectively. In this approach, we transform the given fractional differential equation into an equivalent integral equation. Then we establish sufficient conditions and employ the Schauder fixed point theorem and the method of upper and lower solutions to obtain the existence of a positive solution of a given problem. We also use the Banach contraction principle theorem to show the existence of a unique positive solution. The result of existence obtained by structure the upper and lower control functions of the nonlinear term is without any monotonous conditions. Finally, an example is presented to show the effectiveness of our main results.
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 64, Heft 1, S. 119-132
ISSN: 2065-961X
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 68, Heft 2, S. 279-293
ISSN: 2065-961X
To obtain the main result of the present paper we use the technique of differential subordination. As special cases of our main result, we obtain sufficient conditions for $f\in\mathcal A$ to be $\phi-$like, starlike and close-to-convex in a parabolic region.
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 67, Heft 3, S. 501-511
ISSN: 2065-961X
"In this paper, we show the existence of continuous positive solutions of a class of nonlinear parabolic reaction di usion systems with initial conditions using techniques of functional analysis and potential analysis."
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 65, Heft 1, S. 3-15
ISSN: 2065-961X
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 66, Heft 4, S. 667-675
ISSN: 2065-961X
The notions of strong differential subordination and superordination have been studied recently by many authors. In the present paper, using these concepts, we obtain some preserving properties of certain nonlinear integral operator defined on the space of normalized analytic functions in $\mathbb{D}\times\overline{\mathbb{D}}$. The sandwich-type theorems and consequences of the main results are also considered.
In: Studia Universitatis Babeş-Bolyai. Mathematica, Band 64, Heft 3, S. 367-385
ISSN: 2065-961X