论文标题
在本地有限图的邻接运营商上
On adjacency operators of locally finite graphs
论文作者
论文摘要
如果对于$γ$ $γ$的每个顶点$ v $,则图$γ$称为本地有限的,而所有$ v $ $ v $ in $γ$的$γ(v)$是有限的。对于任何本地有限的图形$γ$,带有顶点套装$ v(γ)$,对于任何字段$ f $,让$ f^{v(γ)} $是所有功能$ v(γ)\ to f $ y to f $ y to f $的矢量空格$ f^{v(γ)} \ to f^{v(γ)} $由$(a^{({{\ rm alg})} _ {γ,f}(f)(f)(v)= \ sum_ {u sum_ {u sum_ {u s inγ(v)} f(v)f(v)f(v) V(γ)$。在有限图的情况下,映射$ a^{(({\ rm alg})} _ {γ,f} $是$γ$(超过$ f $)的邻接矩阵定义的众所周知的操作员,并且是eigenvaluese and eigenfunctions of eigenvaluese and eigenfunctions of the Opterator f. \ Mathbb {C} $)有限图理论的一部分。在本文中,我们取消了$ a^{({{{\ rm alg})} _ {γ,f} $的特征值和特征功能的理论,用于本地无限的图形$γ$(尽管有几个结果可能是有限的$ f $ fields $ f $ fields $ f $)学位和$ f = \ mathbb {c} $。根据作者的意见,以前朝这个方向的尝试并不十分令人满意,因为考虑到相当特殊的特征函数和相应的特征值受到限制。
A graph $Γ$ is called locally finite if, for each vertex $v$ of $Γ$, the set $Γ(v)$ of all neighbors of $v$ in $Γ$ is finite. For any locally finite graph $Γ$ with vertex set $V(Γ)$ and for any field $F$, let $F^{V(Γ)}$ be the vector space over $F$ of all functions $V(Γ) \to F$ (with natural componentwise operations) and let $A^{({\rm alg})}_{Γ,F}$ be the linear operator $F^{V(Γ)} \to F^{V(Γ)}$ defined by $(A^{({\rm alg})}_{Γ,F}(f))(v) = \sum_{u \in Γ(v)}f(u)$ for all $f \in F^{V(Γ)}$, $v \in V(Γ)$. In the case of finite graph $Γ$ the mapping $A^{({\rm alg})}_{Γ,F}$ is the well known operator defined by the adjacency matrix of $Γ$ (over $F$), and the theory of eigenvalues and eigenfunctions of such operator is a well-developed (at least in the case $F = \mathbb{C}$) part of the theory of finite graphs. In this paper we develope a theory of eigenvalues and eigenfunctions of $A^{({\rm alg})}_{Γ,F}$ for arbitrary infinite locally finite graphs $Γ$ (although a few results may be of interest for finite graphs) and fields $F$ with a special emphasis on the case when $Γ$ is connected with uniformly bounded vertex degrees and $F = \mathbb{C}$. By the author opinion, previous attempts in this direction were not quite satisfactory since were limited by consideration of rather special eigenfunctions and corresponding eigenvalues.