English

The A-like matrices for a hypercube

Combinatorics 2010-10-14 v1

Abstract

Let DD denote a positive integer and let QDQ_D denote the graph of the DD-dimensional hypercube. Let XX denote the vertex set of QDQ_D and let A\MXA \in \MX denote the adjacency matrix of QDQ_D. A matrix B\MXB \in \MX is called AA-{\em like} whenever both (i) BA=ABBA = AB; (ii) for all x,yXx,y \in X that are not equal or adjacent, the (x,y)(x,y)-entry of BB is zero. Let \Al\Al denote the subspace of \MX\MX consisting of the AA-like elements. We decompose \Al\Al into the direct sum of its symmetric part and antisymmetric part. We give a basis for each part. The dimensions of the symmetric part and antisymmetric part are D+1D+1 and (D2){D \choose 2}, respectively.

Keywords

Cite

@article{arxiv.1010.2606,
  title  = {The A-like matrices for a hypercube},
  author = {Stefko Miklavic and Paul Terwilliger},
  journal= {arXiv preprint arXiv:1010.2606},
  year   = {2010}
}
R2 v1 2026-06-21T16:27:48.188Z