Bilinear forms graph smallest eigenvalue conjecture

About 5 years old · traced to

Let Hq(d,e)H_q(d,e) be the bilinear forms scheme on the d×ed\times e matrices over Fq\mathbb{F}_q, where d≤ed\leq e. In its distance-jj graph, write Bj(i)B_j(i) for the eigenvalue indexed by ii, with 0≤i,j≤d0\leq i,j\leq d.

Bilinear forms eigenvalue conjecture. For q≥3q\geq 3, or q=2q=2 and d≠ed\neq e, Bj(d−j+1)B_j(d-j+1) is the smallest eigenvalue in the distance-jj graph for 1≤j≤d1\leq j\leq d.

The conjecture was previously proved for q≥4q\geq 4 and is proved in this paper for all q≥2q\geq 2, so the claim is now resolved.

References

Primary source

Sebastian M. Cioabă and Himanshu Gupta, “On the eigenvalues of Grassmann graphs, Bilinear forms graphs and Hermitian forms graphs”, arXiv:2102.10155 (2021).

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.