Beiranvand, A. Ghazanfari, Amir Ghasem
Published in
Mathematica Slovaca

In this paper, we present numerous refinements of the Young inequality by the Kantorovich constant. We use these improved inequalities to establish corresponding operator inequalities on a Hilbert space and some new inequalities involving the Hilbert-Schmidt norm of matrices. We also give some refinements of the following Heron type inequality for ...

Koščová, Michaela Harman, Radoslav Mačutek, Ján
Published in
Mathematica Slovaca

The problem of iterated partial summations is solved for some discrete distributions defined on finite supports. The power method, usually used as a computational approach to the problem of finding matrix eigenvalues and eigenvectors, is in some cases an effective tool to prove the existence of the limit distribution, which is then expressed as a s...

Banakh, Taras Filipczak, Małgorzata Wódka, Julia
Published in
Mathematica Slovaca

A function f : X → ℝ defined on a topological space X is called returning if for any point x ∈ X there exists a positive real number Mx such that for every path-connected subset Cx ⊂ X containing the point x and any y ∈ Cx ∖ {x} there exists a point z ∈ Cx ∖ {x, y} such that |f(z)| ≤ max{Mx, |f(y)|}. A topological space X is called path-inductive i...

Fišnarová, Simona Mařík, Robert
Published in
Mathematica Slovaca

Neutral differential equations are one of the most important extensions of classical ordinary differential equations and aim to give a better explanation for modeling phenomena where ordinary differential equations are insufficient. Naturally, all the questions studied in the scope of ordinary differential equations attracted the attention also for...

Barzegar, Hasan
Published in
Mathematica Slovaca

For a class 𝓜 of monomorphisms of a category, mathematicians usually use different types of essentiality. Essentiality is an important notion closely related to injectivity. Banaschewski defines and gives sufficient conditions on a category 𝓐 and a subclass 𝓜 of its monomorphisms under which 𝓜-injectivity well-behaves with respect to the notions su...

Došenović, Tatjana Kadelburg, Zoran D. Mitrović, Zoran Radenović, Stojan
Published in
Mathematica Slovaca

Z. D. Mitrović and S. Radenović introduced in [The Banach and Reich contractions in bv(s)-metric spaces, J. Fixed Point Theory Appl. 19 (2017), 3087–3095] a new class of generalized metric spaces and proved some fixed point theorems in this framework. The purpose of this paper is to consider other kinds of contractive mappings in bv(s)-metric space...

Khojasteh, Farshid Khandani, Hassan
Published in
Mathematica Slovaca

In this work, the discussion centers on introducing non-triangular metric as a generalization of JS-metric, which may lessen the frantic pace of working on generalizing the triangle inequality by omitting it from the original ordinary metric’s definition. Then, we present S-operators as a new sort of mappings included some properties in order to ch...

Przemska, Emilia
Published in
Mathematica Slovaca

The question as to the number of sets obtainable from a given subset of a topological space using the operators derived by composing members of the set {b, i, ∨, ∧}, where b, i, ∨ and ∧ denote the closure operator, the interior operator, the binary operators corresponding to union and intersection, respectively, is called the Kuratowski {b, i, ∨, ∧...

Maity, Dipendu Upadhyay, Ashish Kumar
Published in
Mathematica Slovaca

If the face-cycles at all the vertices in a map are of same type then the map is said to be a semi-equivelar map. There are eleven types of semi-equivelar maps on the torus. In 1972 Altshuler has presented a study of Hamiltonian cycles in semi-equivelar maps of three types {36}, {44} and {63} on the torus. In this article we study Hamiltonicity of ...

Bozdağ, Hacer Kiliç, Emrah Akkus, Ilker
Published in
Mathematica Slovaca

In this paper, two new analogues of the Hilbert matrix with four-parameters have been introduced. Explicit formulæ are derived for the LU-decompositions and their inverses, and the inverse matrices of these analogue matrices.