Zobrazeno 1 - 10
of 16
pro vyhledávání: '"Oswaldo Araujo"'
Publikováno v:
International Journal of Mathematics and Mathematical Sciences, Vol 2005, Iss 10, Pp 1565-1576 (2005)
Given a graph G with n vertices, let p(G,j) denote the number of ways j mutually nonincident edges can be selected in G. The polynomial M(x)=∑j=0[n/2](−1)jp(G,j)xn−2j, called the matching polynomial of G, is closely related to the Hosoya index
Externí odkaz:
https://doaj.org/article/010db34699e74ee7a31cffbdace6396a
Autor:
Milton Oswaldo Araujo, Maria Dolores Justicia Andrade, José Ricardo Negrete Ocampo, Katherine Romero
Publikováno v:
Revista Medica Vozandes. 30
Autor:
Juan Rada, Oswaldo Araujo
Publikováno v:
Discrete Applied Mathematics. 119:287-295
We show that for every integer h⩾0, the higher order connectivity index hχ(T) of a starlike tree T (a tree with unique vertex of degree >2) is completely determined by its branches of length ⩽h. As a consequence, we show that starlike trees whic
Publikováno v:
Applied Mathematics Letters. 14(7):843-848
Let m ( G,k ) be the number of k -matchings in the graph G . We write G 1 ⪯ G 2 if m ( G 1 , k ) ≤ m ( G 2 , k ) for all k = 1, 2,…. A tree is said to be starlike if it possesses exactly one vertex of degree greater than two. The relation T 1
Autor:
Juan Rada, Oswaldo Araujo
Publikováno v:
Journal of Mathematical Chemistry. 27:201-212
Let T be a tree and consider the Randic index χ(T)=∑ $$_{vi - vj} (1/\sqrt {\delta (v_i )\delta (v_j )} )$$ ), where v i –v j runs over all edges of T and δ(v i ) denotes the degree of the vertex v i . Using counting arguments we show that the
Autor:
Oswaldo Araujo, J. A. de la Peña
Publikováno v:
Linear Algebra and its Applications. 283(1-3):171-177
Let G be a simple graph and consider the m-connectivity index m X(G) = ∑ i 1 − i n hellip; i m+1 ,1 d i 1 d i m … d i m+1 , where i 1 − i 2 −⇝−i m+1 runs over all paths of length m in G and di denotes the degree of the vertex i. We find
Autor:
Oswaldo Araujo, Daniel A. Morales
Publikováno v:
Journal of Chemical Information and Computer Sciences. 38:1031-1037
A recently proposed procedure for orthogonalization of graph theoretical invariants, based on Galois theory, is applied to the elucidation of structure−property relations. The properties of the new procedure are described on a correlation of the bo
Autor:
J. A. de la Peña, Oswaldo Araujo
Publikováno v:
Journal of Chemical Information and Computer Sciences. 38:827-831
Let G be a simple graph. We say that G is a chemical graph if G is connected and the degree di ≤ 4 for every vertex i. We consider the connectivity index 1χ(G) of a chemical graph G. We use some graph theoretic constructions to find bounds for 1χ
Autor:
Oswaldo Araujo, Daniel A. Morales
Publikováno v:
Journal of Molecular Structure: THEOCHEM. 417:241-246
Analytical formulas for the Randic index of different compounds are derived based on the fact that this index belongs to the vector space Q (√2, √3) over the field Q of the rational numbers. It is shown that for compounds of general formula C n w
Autor:
Oswaldo Araujo, Daniel A. Morales
Publikováno v:
Chemical Physics Letters. 257:393-396
In this work we show that the underlying structure of some graph theoretical invariants used to describe molecular structure, is the vector space Q(√2, √3) over the field Q of the rational numbers. On Q(√2, √3) we define a symmetric bilinear