Leading Giant graviton expansion of Schur correlators in large representations

We consider 4d N=4 $U(N)$ SYM and the leading giant graviton correction to the Schur defect 2-point functions of 1/2-BPS Wilson lines in rank-k symmetric and antisymmetric representations. We study in particular the large k limit for the symmetric case and the regime 1 k N in the antisymmetric one. We present exact results for the correction in agreement with matrix model evaluation at finite $N,k$. The Wilson lines in symmetric/antisymmetric representations admit a description in terms of D3ₖ and D5ₖ brane probes representing a collection of k fundamental strings. In this picture, giant graviton corrections come from fluctuations of brane probes in presence of a wrapped D3 brane giant graviton. In particular, for the antisymmetric case, our leading correction matches the half-index of the 3d N=4 Maxwell theory living on the 3d disk which is a part of the giant graviton divided out by the D5ₖ probe, as recently proposed in arXiv:2404.08302. For the symmetric case at large k, we derive an explicit exact residue formula for the leading correction.