Eigenvalue bounds in the critical regime

Prove the conjectured upper bound for the ordered eigenvalues of the asymptotic covariance matrix of a vector of normalized volume power functionals in the critical regime, assuming that the matrices \(A_m^{>1}\) satisfy Requirement 1, namely \(0\leq\lambda_1^{\Sigma_n}\leq\cdots\leq\lambda_n^{\Sigma_n}\leq (k_n+1)\max_{m=0,\ldots,k_n} S_m\left(\sum_{i=1}^n a_{i,m}^{-2}\right)\).

Background

In the critical regime, the covariance matrix is expressed as a finite weighted sum of matrices Am<1A_m^{<1} or Am>1A_m^{>1}, depending on the value of the limiting parameter cc. The paper derives upper bounds for the eigenvalues of each individual matrix Am>1A_m^{>1} using spectral norms.

The proposed bound for the full covariance matrix requires Requirement 1, a Loewner-order domination condition that the paper notes may not generally be satisfied. The resulting statement is explicitly presented as a conjecture and is used later to obtain variance bounds for hh-functionals.

References

Now we are able to give the following conjecture for $\Sigma_n $ in the critical regime.

Covariance matrices of volume power functionals of random simplicial complexes -- an asymptotic analysis  (2509.15790 - Westenholz, 19 Sep 2025) in Conjecture 7.13 (Section \ref{Section: volume power functional}, subsection 'Critical regime'); cited in Applications, Section \ref{Sec: stoch. appl.}