Mark Sequences in Digraphs

More skew-equienergetic digraphs

Two digraphs of same order are said to be skew-equienergetic if their skew energies are equal. One of the open problems proposed by Li and Lian was to construct non-cospectral skew-equienergetic digraphs on n vertices. Recently this problem was solved by Ramane et al. In this  paper, we give some new methods to construct new skew-equienergetic digraphs.

Unidigraphic and unigraphic degree sequences through uniquely realizable integer-pair sequences

In this paper we use the concept of integer-pair sequences, an invariant of graphs and digraphs introduced in Hakimi and Patrinos [9], and results on its unique realizability, in Das [4,5], to obtain results on the unique realizability of degree sequences, another invariant of graphs and digraphs. We thus present a unified approach to solving the problem of unique realizability of these two inv...

Vertex Removable Cycles of Graphs and Digraphs

‎In this paper we defined the vertex removable cycle in respect of the following‎, ‎if $F$ is a class of graphs(digraphs)‎ ‎satisfying certain property‎, ‎$G in F $‎, ‎the cycle $C$ in $G$ is called vertex removable if $G-V(C)in in F $.‎ ‎The vertex removable cycles of eulerian graphs are studied‎. ‎We also characterize the edge removable cycles of regular‎ ‎graphs(digraphs).‎    

A Procedure: Common Part of Two Digraphs

Sufficient conditions on the zeroth-order general Randic index for maximally edge-connected digraphs

Let D be a digraph with vertex set V(D) .For vertex v V(D), the degree of v, denoted by d(v), is defined as the minimum value if its out-degree  and its in-degree . Now let D be a digraph with minimum degree  and edge-connectivity If  is real number, then the zeroth-order general Randic index is defined by   .  A digraph is maximally edge-connected if . In this paper we present sufficient condi...