Question

How does one define locality in a discrete system?

Answer 1

Consider a discrete system, such as a spin chain or spin net. Generally I think we can define such as system as a (undirected) graph, with various quantum operators (such as spin operators) "living" on the vertices. The Hilbert space is then spanned by the eigenvectors of the operators at all the vertices. How then do we explicitly define what we mean by local. The graph gives a natural notion of distance (in terms of how many edges must be traversed to get from one vertex to another), so does local mean "less than some distance R", or simply "containing a finite number of vertices"

Answer 2

Heya....

Question :- How does one define locality in a discrete system?

Answer :- Refer to attachment