A connected graph G is said to be neighbourly irregular graph if no two adjacent vertices of G have same degree. In this paper we obtain neighbourly irregular derived graphs such as semitotal-point graph, k^{tℎ} semitotal-point graph, semitotal-line graph, paraline graph, quasi-total graph and quasivertex-total graph and also neighbourly irregular of some graph products.

the concept of the bipartite divisor graph for integer subsets has been considered in [‎graph combinator., ‎ 26 (2010) 95--105‎.]. ‎in this paper‎, ‎we will consider this graph for the set of character degrees of a finite group $g$ and obtain some properties of this graph‎. ‎we show that if $g$ is a solvable group‎, ‎then the number of connected components of this graph is at most $2$ and if $g...

We consider a perturbed graph consisting of two infinite edges, loop, and glued arbitrary finite γε with small where is obtained by ε−1 times contraction some fixed ε parameter. On the graph, we Schrödinger operator whose potential on edges can singularly depend Kirchhoff condition at internal vertices Dirichlet or Neumann boundary vertices. For eigenvalue corresponding eigenfunction prove holo...

two digraphs of same order are said to be skew-equienergetic if theirskew energies are equal. one of the open problems proposed by li andlian was to construct non-cospectral skew-equienergetic digraphs onn vertices. recently this problem was solved by ramane et al. inthis paper, we give some new methods to construct new skew-equienergeticdigraphs.

In the field of wireless communication, increasing number devices makes limited spectrum resources more scarce and accelerates complexity electromagnetic environment, posing a serious threat to sustainability industry’s development. Therefore, new effective technical methods are needed mine analyze activity rules reduce risk frequency conflict. This paper introduces idea graphs proposes resourc...

in this paper we study the coprime graph of a group $g$. the coprime graph of a group $g$, is a graph whose vertices are elements of $g$ and two distinct vertices $x$ and $y$ are adjacent iff $(|x|,|y|)=1$. in this paper we classify all the groups which the coprime graph is a complete r-partite graph or a planar graph. also we study the automorphism group of the coprime graph.