Weighted Turán conjecture for two-dimensional vector weights

Let ω\omega be sufficiently large and let G=(V,E)G=(V,E) be a graph with clique number ω\omega. Assign a vector \vviR2\vv_i\in\mathbb R^2 to each vertex ii, and define

\wwi,j=\vvi,\vvj2\ww_{i,j}=\langle\vv_i,\vv_j\rangle^2

for each pair of vertices (i,j)(i,j). Suppose that \vvi,\vvj0\langle\vv_i,\vv_j\rangle\geq0 for every {i,j}E\{i,j\}\in E. Weighted Turán conjecture. Then

{i,j}E\wwi,j12(11ω)i,jV\wwi,j,\sum_{\{i,j\}\in E}\ww_{i,j}\leq\frac12\left(1-\frac1\omega\right)\sum_{i,j\in V}\ww_{i,j},

where the sum on the left counts each edge once.

This is presented as a weighted analogue of Turán's theorem and as a reformulation of the preceding conjecture on χvec,3(G)\chi_{\mathrm{vec},3}”(G); no resolution is given in the source.

Sources & referencesView supporting material

Primary source

Gabriel Coutinho, Thomás Jung Spier and Shengtong Zhang, “Conic programming to understand sums of squares of eigenvalues of graphs”, arXiv:2411.08184 (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.