English

On the edge reconstruction of six digraph polynomials

Combinatorics 2023-05-16 v1

Abstract

Let G=(V,E)G=(V,E) be a digraph having no loops and no multiple arcs, with vertex set V={v1,v2,,vn}V=\{v_1,v_2,\ldots,v_n\} and arc set E={e1,e2,,em}E=\{e_1,e_2,\ldots,e_m\}. Denote the adjacency matrix and the vertex in-degree diagonal matrix of GG by A=(aij)n×nA=(a_{ij})_{n\times n} and D=diag(d+(v1),d+(v2),,d+(vn))D=diag(d^+(v_1),d^+(v_2),\cdots,d^+(v_n)), where aij=1a_{ij}=1 if (vi,vj)E(G)(v_i,v_j)\in E(G) and aij=0a_{ij}=0 otherwise, and d+(vi)d^+(v_i) is the number of arcs with head viv_i. Set f1(G;x)=det(xIA),f2(G;x)=det(xID+A),f3(G;x)=det(xIDA),f4(G;x)=per(xIA),f5(G;x)=per(xID+A),f6(G;x)=per(xIDA)f_1(G;x)=\det(xI-A), f_2(G;x)=\det(xI-D+A),f_3(G;x)=\det(xI-D-A),f_4(G;x)={\rm per}(xI-A), f_5(G;x)={\rm per}(xI-D+A),f_6(G;x)={\rm per}(xI-D-A), where det(X)\det(X) and per(X){\rm per}(X) denote the determinant and the permanent of a square matrix XX, respectively. In this paper, we consider a variant of the Ulam's vertex reconstruction conjecture and the Harary's edge reconstruction conjecture, and prove that, for any 1i61\leq i\leq 6, \begin{equation*} (m-n)f_i(G;x)+xf_i'(G;x)=\sum\limits_{e\in E}f_i(G-e;x), \end{equation*} which implies that if mnm\neq n, then fi(G;x)f_i(G;x) can be reconstructed from {fi(Ge;x)eE}\{f_i(G-e;x)|e\in E\}.

Keywords

Cite

@article{arxiv.2305.07913,
  title  = {On the edge reconstruction of six digraph polynomials},
  author = {Jingyuan Zhang and Xian'an Jin and Weigen Yan},
  journal= {arXiv preprint arXiv:2305.07913},
  year   = {2023}
}
R2 v1 2026-06-28T10:33:40.296Z