Persistence of small-frequency spectral peak under higher j_max truncation

Ascertain whether the peak structure at small frequency observed in the ratio ρ^{xy}(ω)/ω of the stress-energy tensor spectral function for 2+1-dimensional SU(2) gauge theory persists when the local Hilbert space truncation parameter j_max is increased beyond 1/2, by computing the relevant off-diagonal matrix elements of \widetilde{T}^{xy} at higher j_max and analyzing the resulting spectral function.

Background

The authors compute the spectral function derived from retarded correlators of T^{xy} on a 4×4 honeycomb lattice with j_max = 1/2 and find a peak in ρ^{xy}(ω)/ω at small ω, contrasting with the flat behavior reported in holographic strong-coupling results and resembling perturbative QCD trends.

They highlight that the observed peak may be affected by local Hilbert space truncation, and thus propose increasing j_max to test the robustness of the peak structure. This requires recomputing |⟨n|\widetilde{T}^{xy}|m⟩| and reassessing the small-ω behavior under reduced truncation artifacts.