منابع مشابه
Spectra of Some New Graph Operations and Some New Class of Integral Graphs
In this paper, we define duplication corona, duplication neighborhood corona and duplication edge corona of two graphs. We compute their adjacency spectrum, Laplacian spectrum and signless Laplacian. As an application, our results enable us to construct infinitely many pairs of cospectral graphs and also integral graphs.
متن کاملSome families of integral graphs
A graph is called integral if all its eigenvalues (of the adjacency matrix) are integers. In this paper, the graphs K1,r •Kn , r ∗Kn , K1,r • Km,n , r ∗ Km,n and the tree K1,s • T (q, r,m, t) are defined. We determine the characteristic polynomials of these graphs and also obtain sufficient and necessary conditions for these graphs to be integral. Some sufficient conditions are found by using t...
متن کاملSome new results using Hadamard fractional integral
Fractional calculus is the field of mathematical analysis which deals with the investigation and applications of integrals and derivatives of arbitrary order. The purpose of this work is to use Hadamard fractional integral to establish some new integral inequalities of Gruss type by using one or two parameters which ensues four main results . Furthermore, other integral inequalities of reverse ...
متن کاملNonexistence of Some 4-regular Integral Graphs
A graph is called integral if all its eigenvalues are integers. The quest for integral graphs was initiated by F. Harary and A. J. Schwenk [9]. All such cubic graphs were obtained by D. Cvetković and F. C. Bussemaker [2, 1], and independently by A. J. Schwenk [10]. There are exactly thirteen cubic integral graphs. In fact, D. Cvetković [2] proved that the set of regular integral graphs of a fix...
متن کاملSome Results On Q-Integral Graphs
We consider the problem of determining the Q–integral graphs, i.e. the graphs with integral signless Laplacian spectrum. First, we determine some infinite series of such graphs having the other two spectra (the usual one and the Laplacian) integral. We also completely determine all (2, s)–semiregular bipartite graphs with integral signless Laplacian spectrum. Finally, we give some results conce...
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ژورنال
عنوان ژورنال: Applicable Analysis and Discrete Mathematics
سال: 2007
ISSN: 1452-8630
DOI: 10.2298/aadm0702420i