The multi-edge Laplacian matching root integral variation conjecture

Let GG be a connected graph, let FE(Gc)F\subseteq E(G^c) be nonempty, and set H=G+FH=G+F. Let λ1(G),,λn(G)\lambda_1(G),\dots,\lambda_n(G) denote the roots of the Laplacian matching polynomial of GG. Multi-edge LMRIV conjecture. Multi-edge Laplacian matching root integral variation does not occur for GG: there are no integers t1,,tnZ0t_1,\dots,t_n\in\mathbb Z_{\geq 0} with t1++tn=2Ft_1+\cdots+t_n=2|F| such that, as multisets,

{λ1(H),,λn(H)}={λ1(G)+t1,,λn(G)+tn}.\{\lambda_1(H),\dots,\lambda_n(H)\}=\{\lambda_1(G)+t_1,\dots,\lambda_n(G)+t_n\}.

The conjecture has been verified by computer for n9n\leq 9; it generalizes the one-edge patterns corresponding to one-place and two-place LMRIV and remains open in general.

Sources & referencesView supporting material

Primary source

Sebastian M. Cioabă, Lele Liu and Yi Wang, “Two-place Laplacian matching root integral variations are impossible”, arXiv:2605.01760 (2026).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.