English

Isospectral reductions and quantum walks on graphs

Combinatorics 2022-12-02 v1

Abstract

We give a new formula for computing the isospectral reduction of a matrix (and graph) down to a submatrix (or subgraph). Using this, we generalize the notion of isospectral reductions. In addition, we give a procedure for constructing a matrix whose isospectral reduction down to a submatrix is given. We also prove that the isospectral reduction completely determines the restriction of the quantum walk transition matrix to a subset. Using these, we construct new families of simple graphs exhibiting perfect quantum state transfer.

Keywords

Cite

@article{arxiv.2212.00172,
  title  = {Isospectral reductions and quantum walks on graphs},
  author = {Mark Kempton and John Tolbert},
  journal= {arXiv preprint arXiv:2212.00172},
  year   = {2022}
}
R2 v1 2026-06-28T07:18:51.161Z