be the Laplacian matrix of G. When G is a tree or a bipartite graph we obtain bounds for the permanent of L(G) both in terms of n only and in terms of d 1 ..... d,. Improved bounds are obtained in terms of the diameter of T and the size of a matching in T.
Permanent of the laplacian matrix of trees with a given matching
โ Scribed by John L Goldwasser
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 715 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
We define the Laplacian ratio of a tree z(T), to be the permanent of the Laplacian matrix of T divided by the product of the degrees of the vertices. Best possible lower and upper bounds are obtained for ~r(T) in terms of the size of the largest matching in T.
๐ SIMILAR VOLUMES
## Abstract Let ฮป~__k__~(__G__) be the __k__th Laplacian eigenvalue of a graph __G__. It is shown that a tree __T__ with __n__ vertices has $\lambda\_{k}(T)\le \lceil { {n}\over{k}}\rceil$ and that equality holds if and only if __k__ < __n__, __k__|__n__ and __T__ is spanned by __k__ vertex disjoin
Define the perrank of a matrix A to be the size of the largest square submatrix of A with nonzero permanent. Motivated in part by the Alon Jaeger Tarsi Conjecture [3], we prove several results on perranks..
A limb of a tree is the union of one or more branches at a vertex in the tree, where a branch of a tree at a vertex is a maximal subtree containing the given vertex as an end-vertex. In this note, we first consider the enumeration of trees (undirected, oriented or mixed) with forbidden limbs. The en