pp 271-276 August 2015
A note on neighborhood total domination in graphs
Let 𝐺 = (𝑉 ,𝐸) be a graph without isolated vertices. A dominating set 𝑆 of 𝐺 is called a neighborhood total dominating set (or just NTDS) if the induced subgraph 𝐺[𝑁(𝑆)] has no isolated vertex. The minimum cardinality of a NTDS of 𝐺 is called the neighborhood total domination number of 𝐺 and is denoted by 𝛾_{nt}(𝐺). In this paper, we obtain sharp bounds for the neighborhood total domination number of a tree. We also prove that the neighborhood total domination number is equal to the domination number in several classes of graphs including grid graphs.
pp 277-290 August 2015
On the coefficient conjecture of Clunie and Sheil-Small on univalent harmonic mappings
In this paper, we first prove the coefficient conjecture of Clunie and Sheil-Small for a class of univalent harmonic functions which includes functions convex in some direction. Next, we prove growth and covering theorems and some related results. Finally, we propose two conjectures, an affirmative answer to one of which would then imply, for example, a solution to the conjecture of Clunie and Sheil-Small.
pp 291-306 August 2015
Certain fractional integral operators and the generalized multi-index Mittag-Leffler functions
Praveen Agarwal Sergei V Rogosin Juan J Trujillo
In this paper, we obtain formulas of fractional integration (of Marichev–Saigo–Maeda type) of the generalized multi-index Mittag-Leffler functions 𝐸_{𝛾,𝜅}[(𝛼_{𝑗}, 𝛽_{𝑗})_{𝑚}; 𝑧] generalizing 2𝑚-parametric Mittag-Leffler functions studied by Saxena and Nishimoto (J. Fract. Calc. 37 (2010) 43–52). Some interesting special cases of our main results are considered too.
pp 307-321 August 2015
Soliton solutions for a quasilinear Schrödinger equation via Morse theory
In this paper, Morse theory is used to show the existence of nontrivial weak solutions to a class of quasilinear Schrödinger equation of the form
$$-\Delta u - \frac{p}{2^{p-1}} u \Delta_p (u^2) = f(x, u)$$
in a bounded smooth domain $\Omega \subset \mathbb{R}^N$ with Dirichlet boundary condition.
pp 323-351 August 2015
Syed Abbas V Kavitha R Murugesu
In this article, we study the concept of Stepanov-like weighted pseudo almost automorphic solutions to fractional order abstract integro-differential equations. We establish the results with Lipschitz condition and without Lipschitz condition on the forcing term. An interesting example is presented to illustrate the main findings. The results proven are new and complement the existing ones.
pp 353-370 August 2015
K R Prasad N Sreedhar M A S Srinivas
In this paper, we establish the existence of positive solutions for systems of second order multi-point boundary value problems on time scales by applying Guo– Krasnosel’skii fixed point theorem.
pp 371-397 August 2015
Some spherical analysis related to the pairs ($U(n),H_n$) and ($U(p, q),H_n$), $p + q = n$
In this paper, we define the normalized spherical transform associated with the generalized Gelfand pair $(U(p, q),H_n)$, where $H_n$ is the Heisenberg group $2n + 1$-dimensional and $p+q = n$. We show that the normalized spherical transform $\mathfrak{F}(f)$ of a Schwartz function $f$ on $H_n$ restricted to the spectrum of the Gelfand pair ($U(n),H_n$) is the Gelfand transform $\hat{g}$ of a radial Schwartz function $g$ on $H_n$. Moreover, by the Godement–Plancherel inversion formula the function $g$ can be recovered explicitly from $\mathfrak{F}(f)$.
pp 399-412 August 2015
Functional equations in matrix normed spaces
Jung Rye Lee Choonkil Park Dong Yun Shin
Using the fixed point method, we prove the Hyers–Ulam stability of the Cauchy additive functional equation and the quadratic functional equation in matrix normed spaces.
pp 413-447 August 2015
P Dutt Akhlaq Husain A S Vasudeva Murthy C S Upadhyay
This is the second of a series of papers devoted to the study of $h-p$ spectral element methods for three dimensional elliptic problems on non-smooth domains. The present paper addresses the proof of the main stability theorem.We assume that the differential operator is a strongly elliptic operator which satisfies Lax–Milgram conditions. The spectral element functions are non-conforming. The stability estimate theorem of this paper will be used to design a numerical scheme which give exponentially accurate solutions to three dimensional elliptic problems on non-smooth domains and can be easily implemented on parallel computers.
Current Issue
Volume 129 | Issue 3
June 2019
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