given a graph $g$, let $g^sigma$ be an oriented graph of $g$ with the orientation $sigma$ and skew-adjacency matrix $s(g^sigma)$. then the spectrum of $s(g^sigma)$ consisting of all the eigenvalues of $s(g^sigma)$ is called the skew-spectrum of $g^sigma$, denoted by $sp(g^sigma)$. the skew energy of the oriented graph $g^sigma$, denoted by $mathcal{e}_s(g^sigma)$, is defined as the sum of the n...

amonge other things we give sufficient and necessary conditions for the lau product of banachalgebras to be biflat or biprojective.

Tanulmányomban Daniel Klesch két eddig kiadatlan levelét közlöm, amelyeket 1677 nyarán küldött a császári udvari könyvtár vezetőjének, I. Lipót császár bizalmasának, történész-tudós Peter Lambecknek. A forrásközlésekhez tartozó tanulmányban levelek nyelvfilozófiai és poetológiai elágazásait vizsgálom meg részletesebben. Az iglói lelkész már németországi száműzetéséből küldte leveleit nyilvánval...

in this paper, we give a characterization of strongly jordan zero-product preserving maps on normed algebras as a generalization of  jordan zero-product preserving maps. in this direction, we give some illustrative examples to show that the notions of strongly zero-product preserving maps and strongly jordan zero-product preserving maps are completely different. also, we prove that the direct p...

let g be a simple connected graph. the generalized polarity wiener index ofg is defined as the number of unordered pairs of vertices of g whosedistance is k. some formulas are obtained for computing the generalizedpolarity wiener index of the cartesian product and the tensor product ofgraphs in this article.

abstract: in the present paper, we give a necessary and sufficient condition for contact cr-warped product to be contact cr-product in kenmotsu space forms.