Laplacian zero-eigenvalue multiplicity conjecture for connected uniform hypergraphs

Let HH be a connected kk-uniform hypergraph, let L(H)\mathcal{L}(H) be its Laplacian tensor, let A(H)\mathcal{A}(H) be its adjacency tensor, and let ρ\rho be the spectral radius of A(H)\mathcal{A}(H). Write am(0,L(H))\mathrm{am}(0,\mathcal{L}(H)) and am(ρ,A(H))\mathrm{am}(\rho,\mathcal{A}(H)) for the corresponding algebraic multiplicities, and let V0(L(H))\mathbb{V}_0(\mathcal{L}(H)) denote the projective eigenvariety for the zero eigenvalue. Laplacian zero-eigenvalue multiplicity conjecture.

am(0,L(H))=am(ρ,A(H)),\mathrm{am}(0,\mathcal{L}(H))=\mathrm{am}(\rho,\mathcal{A}(H)),

and consequently

am(0,L(H))=V0(L(H)).\mathrm{am}(0,\mathcal{L}(H))=|\mathbb{V}_0(\mathcal{L}(H))|.

The first equality is established in the paper for kk-uniform hypertrees, and the authors propose its extension to all connected kk-uniform hypergraphs; the consequence then follows from the relation between the corresponding projective eigenvarieties.

Sources & referencesView supporting material

Primary source

Yi-Zheng Fan, “The multiplicity of eigenvalues of nonnegative weakly irreducible tensors and uniform hypergraphs”, arXiv:2410.20830 (2024).

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.