arXiv subjects
Publications and source records attributed to Branko Malesevic.
In this paper we analyse Cline's matrix equation, generalized Penrose's matrix system and a matrix system for k-commutative {1}-inverses. We determine reproductive and non-reproductive general solutions of analysed matrix equation and analysed matrix systems.
In this article we consider a consistent matrix equation $AXB = C$ when a particular solution $X_{0}$ is given and we represent a new form of the general solution which contains both reproductive and non-reproductive solutions (it depends on the form of particular solution $X_{0}$). We also analyse the solutions of some matrix systems using the concept of reproductivity and we give a new form of the condition for the consistency of the matrix equation $AXB=C$.
This paper deals with reduction of non-homogeneous linear systems of first order operator equations with constant coefficients. An equivalent reduced system, consisting of higher order linear operator equations having only one variable and first order linear operator equations in two variables, is obtained by using the rational canonical form.
In this paper we use Groebner bases theory in order to determine planarity of intersections of two algebraic surfaces in ${\bf R}^3$. We specially considered plane sections of certain type of conoid which has a cubic egg curve as one of the directrices. The paper investigates a possibility of conic plane sections of this type of conoid.
The aim of this paper is to exhibit a method for proving that certain analytic functions are not solutions of algebraic differential equations. The method is based on model-theoretic properties of differential fields and properties of certain known transcendental differential functions, as of $Γ(x)$. Furthermore, it also determines differential transcendency of solution of some functional equations.
In this paper we consider some analytical relations between gamma function $Γ(z)$ and related functions such as the Kurepa's function $K(z)$ and alternating Kurepa's function $A(z)$. It is well-known in the physics that the Casimir energy is defined by the principal part of the Riemann function $ζ(z)$ (Blau, Visser, Wipf; Elizalde). Analogously, we consider the principal parts for functions $Γ(z)$, $K(z)$, $A(z)$ and we also define and consider the principal part for arbitrary meromorphic functions. Next, in this paper we consider some differential-algebraic $($d.a.$)$ properties of functions $Γ(z)$, $ζ(z)$, $K(z)$, $A(z)$. As it is well-known (H\" older; Ostrowski) $Γ(z)$ is not a solution of any d.a. equation. It appears that this property of $Γ(z)$ is universal. Namely, a large class of solutions of functional differential equations also has that property. Proof of these facts is reduced, by the use of the theory of differential algebraic fields (Ritt; Kaplansky; Kolchin), to the d.a. transcendency of $Γ(z)$.
We give a new procedure in Maple for finding the k-th power of a martix. The algorithm is based on the article [1].
In this paper we consider alternating Kurepa's function $A(z)$ \cite{Petojevic_02}. We give some recurrent relations for alternating Kurepa's function via appropriate sequences of rational functions and gamma function. Also we give some inequalities for the real part of alternating Kurepa's function $A(x)$ for values of argument $x>-2$. The obtained results are analogous to results from \cite{Malesevc_04}.
In this paper we consider Kurepa's function $K(z)$ \cite{Kurepa_71}. We give some recurrent relations for Kurepa's function via appropriate sequences of rational functions and gamma function. Also, we give some inequalities for Kurepa's function $K(x)$ for positive values of $x$.