Supported by National Natural Science Foundation of China (Grant No. 10871204) and the Fundamental Research Funds for the Central Universities (Grant No. 09CX04003A)
This paper presents some bounds on the number of Laplacian eigenvalues contained in various subintervals of [0, n] by using the matching number and edge covering number for G, and asserts that for a connected graph th...
Supported by the National Natural Science Foundation of China (Grant No.10871204)
Let T(n,i) be the set of all trees with order n and matching number i.We determine the third to sixth trees in T(2i + 1,i) and the third to fifth trees in T(n,i) for n ≥ 2i + 2 with the largest Laplacian spec...
Supported by National Natural Science Foundation of China(10871204)
Some sharp upper bounds of Laplacian spectral radius of trees in terms of order,diameter,pendant vertex number,covering number,edge covering number or total independence number are given.And the ninth to thirteenth la...
supported by National Natural Science Foundation of China (Grant No.10871204);the Fundamental Research Funds for the Central Universities (Grant No.09CX04003A)
In this paper,we determine graphs with the largest Laplacian spectral radius among the unicyclic and the bicyclic graphs on n vertices with k pendant vertices,respectively.