The Grothendieck Constant is Strictly Larger than Davie-Reeds' Bound
This paper proves that a known lower bound for the Grothendieck constant, established by Davie and Reeds, is not tight. By performing a perturbative analysis of their operator, the authors show that introducing small cubic perturbations increases the integrality gap. This demonstrates that the true Grothendieck constant is strictly larger than their previous estimate.