{ "id": "1102.2134", "version": "v3", "published": "2011-02-10T14:52:45.000Z", "updated": "2014-07-08T11:34:53.000Z", "title": "Well-Quasi-Ordering of Matrices under Schur Complement and Applications to Directed Graphs", "authors": [ "Mamadou Moustapha Kanté" ], "comment": "35 pages. Revised version with a section for directed graphs", "journal": "European Journal of Combinatorics 33(8):1820--1841(2012)", "doi": "10.1016/j.ejc.2012.03.034", "categories": [ "math.CO", "cs.DM" ], "abstract": "In [Rank-Width and Well-Quasi-Ordering of Skew-Symmetric or Symmetric Matrices, arXiv:1007.3807v1] Oum proved that, for a fixed finite field $\\mathbf{F}$, any infinite sequence $M_1,M_2,...$ of (skew) symmetric matrices over $\\mathbf{F}$ of bounded $\\mathbf{F}$-rank-width has a pair $i< j$, such that $M_i$ is isomorphic to a principal submatrix of a principal pivot transform of $M_j$. We generalise this result to $\\sigma$-symmetric matrices introduced by Rao and myself in [The Rank-Width of Edge-Coloured Graphs, arXiv:0709.1433v4]. (Skew) symmetric matrices are special cases of $\\sigma$-symmetric matrices. As a by-product, we obtain that for every infinite sequence $G_1,G_2,...$ of directed graphs of bounded rank-width there exist a pair $i